topical media & game development

topical media & game development
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _
game-javascript-math-kennedy-balanceTheEquation.htm / htm

  <html>
  <head>
  <title>Sunny Boy Says Balance the Equation!</title>
  <script language="JavaScript">
  // constants
  var kAddition = '+';
  var kSubtraction = '-';
  var kMultiplication = 'x';
  var kDivision = '\367';  // this is the octal representation of the division sign.
  var kMinOperand = 0;
  var kMaxOperand = 15;
  
  var gCurrentProblem = new simpleAdditionProblem();
  
  // Generic Functions 
  function assert(isTrue, message) { if (!isTrue) { alert(message) } }
  
  function myPop (string){
     var generator=window.open('', 'name', 'width=400,height=100,toolbar=0,scrollbars=0,screenX=200,screenY=200,left=200,top=200');
  
     generator.document.write('<html><head><title>Balance!</title></head><body>');   
     generator.document.write(string);
     generator.document.write('<center><a href="javascript:self.close()">Close</a></center>');
     generator.document.write('</body></html>');
     generator.document.close();
  }
  
  function absoluteValue (value){ if (value < 0) return (-1*value); else return value; }
  
  function getRandomNumberInRange(rangeStart, rangeEnd){
     assert((rangeStart < rangeEnd), "getRandomNumberInRange: Invalid Input range start =" + rangeStart + " and rangeEnd = " + rangeEnd);
     return Math.round(Math.random()*(rangeEnd-rangeStart)+rangeStart);
  }
  
  function getRandomVariableLetter(){
     switch(getRandomNumberInRange(1,6)){
        case 1: return 'b';
        case 2: return 'c';
        case 3: return 'd';
        case 4: return 'm';
        case 5: return 'n';
        case 6: return 'y';
            default: alert("getRandomVariableLetter: bad switch input");
     }
  }
  
  var gPreviousOperation = kAddition;
  function getRandomOperation(){
     switch(gPreviousOperation){
        case kAddition: gPreviousOperation = kSubtraction; break;
        case kSubtraction: gPreviousOperation = kMultiplication; break;
        case kMultiplication: gPreviousOperation = kDivision; break;
        case kDivision: gPreviousOperation = kAddition; break;
            default: alert("getRandomOperation: bad switch input " + gPreviousOperation);
     }
     return gPreviousOperation;
  }
  
  function performOperation (operation, op1, op2){
     switch(operation){
        case kAddition:  return (1*op1)+(1*op2);
            case kSubtraction: return op1-op2;
            case kMultiplication: return op1 * op2;
            case kDivision: return op1/op2;
            default: alert("performOperation() bad input: " + operation);
     }
  }
  
  function getOppositeOperation (operation){
     switch(operation){
        case kAddition:  return kSubtraction;
            case kSubtraction: return kAddition;
            case kMultiplication: return kDivision;
            case kDivision: return kMultiplication;
            default: alert("getOppositeOperation() bad input: " + operation);
     }
  }
  
  // Dynamic HTML writing functions
  function writeTxtAtTDidOptions(tBodyID, string, sizeString, colorString, appendNewLine){
     var tbody = document.getElementById(tBodyID);
     // create holder for accumulated tbody elements and text nodes
     var frag = document.createDocumentFragment();
     
     var font = document.createElement("font");
     font.setAttribute("size", sizeString);
     font.setAttribute("color", colorString);
     var txt = document.createTextNode(string);
     font.appendChild(txt);
     frag.appendChild(font);
     
     if (!tbody.appendChild(frag)) {
        alert("This browser doesn't support dynamic tables.");
     } 
     
     if (appendNewLine) writeNewLineAtTDid(tBodyID);
  }
  
  function writeTxtAtTDid(tBodyID, string){ writeTxtAtTDidOptions(tBodyID, string, "+1", "black", false);}
  
  function writeTabAtTDid(tBodyID){writeTxtAtTDidOptions(tBodyID, "<tab>", "+0", "white", false)}
  
  function writeNewLineAtTDid(tBodyID){
     var tbody = document.getElementById(tBodyID);
     // create holder for accumulated tbody elements and text nodes
     var frag = document.createDocumentFragment();
     
     var newLine = document.createElement("br");
     frag.appendChild(newLine);
     
     if (!tbody.appendChild(frag)) {
        alert("This browser doesn't support dynamic tables.");
     } 
  }
  
  function writeLinkAtTDidOptions(tBodyID, href, label, sizeString, colorString, isUnderlined, appendNewLine){
     var tbody = document.getElementById(tBodyID);
     // create holder for accumulated tbody elements and text nodes
     var frag = document.createDocumentFragment();
     
     var a = document.createElement("a");
     a.setAttribute("href", href); 
     if (!isUnderlined) a.setAttribute("style", "text-decoration: none");
     
     var font = document.createElement("font");
     font.setAttribute("size", sizeString);
     font.setAttribute("color", colorString);
     var txt = document.createTextNode(label);
     font.appendChild(txt);
     a.appendChild(font);
     frag.appendChild(a);
    
     if (!tbody.appendChild(frag)) {
        alert("This browser doesn't support dynamic tables.");
     } 
  
     if (appendNewLine) writeNewLineAtTDid(tBodyID);   
  }
  
  // Remove existing content of an element
  function clearChildNodes(elemID) {
     var elem = document.getElementById(elemID);
     while (elem.childNodes.length > 0) {
        elem.removeChild(elem.firstChild);
     }
  }
  
  // question generating objects
  // each object is responsible for the following methods
  // getWordProblem
  // getNumberSentence
  // getIncorrectNumberSentence
  // getSolutionForVariable
  // getIncorrectSolutionForVariable
  
  // first comes the easy problems
  function getSimpleWordProblem(){return (this.introText + " " + this.operand1 + " " + this.inBetweenText + " " + this.operand2 + " is " + this.rightSideSolution);}
  function getSimpleNumberSentence(){
     if (kMultiplication == this.operation)
        return (this.operand1 + this.operand2 + " = " + this.rightSideSolution);
     else
        return (this.operand1 + " " + this.operation + " " + this.operand2 + " = " + this.rightSideSolution);
  }
  
  function getSimpleIncorrectNumberSentence(){
     var temp = new simpleIncorrectProblemCopier(this);
     return temp;
  }
  
  function getSolutionForVariable(){return this.valueOfVariable;}
  
  function getIncorrectSolutionForVariable(){ 
     var incorrectSolution = getRandomNumberInRange(this.kMinVariableValue, this.kMaxVariableValue); 
     if (incorrectSolution == this.valueOfVariable) incorrectSolution++;
     return incorrectSolution;
  } 
  
  function simpleIncorrectProblemCopier(simpleProblem) {
     this.operation = simpleProblem.operation;
     while (this.operation == simpleProblem.operation) { this.operation = getRandomOperation(); }
     
     this.operand1 = simpleProblem.operand1;
     this.operand2 = simpleProblem.operand2;
     this.rightSideSolution = simpleProblem.rightSideSolution;
     this.variable = simpleProblem.variable; 
     
     assert((this.operand1==this.variable || this.operand2==this.variable), "simpleIncorrectProblemCopier(): variable does not match up with op1 or op2");
     
     if (this.operand1 == this.variable){
        this.valueOfVariable = 
               Math.round(absoluteValue(performOperation(getOppositeOperation(this.operation), this.rightSideSolution, this.operand2)));
     }
     else{
        this.valueOfVariable = 
               Math.round(absoluteValue(performOperation(getOppositeOperation(this.operation), this.rightSideSolution, this.operand1)));
     }
     
     if (this.valueOfVariable == simpleProblem.valueOfVariable) this.valueOfVariable = getRandomNumberInRange(kMinOperand, kMaxOperand);
  
     // public methods
     this.toString = getSimpleNumberSentence;
     this.getNumberSentence = getSimpleNumberSentence;
     
     assert((this.valueOfVariable >= 0), "simpleIncorrectProblemCopier(): valueOfVariable is too small: " + this.valueOfVariable);
  }  
  
  function simpleAdditionProblem() {
     // first lets construct the problem
     // word problem format =   introText op1 inBetweenText op2 is rightSideSolution
     // number sentence format = op1 operation op2 = rightside solution
     // other needed informatin =  variable and valueOfVariable;
     switch(getRandomNumberInRange(1,4)){
        case 1: this.introText = "The sum of"; this.inBetweenText = "and"; break;
        case 2: this.introText = "Increasing"; this.inBetweenText = "by"; break;
        case 3: this.introText = "Total of"; this.inBetweenText = "and"; break;
        case 4: this.introText = "Adding"; this.inBetweenText = "and"; break;
            default: alert("simpleAdditionProblem: bad switch input");
     }
     this.operation = kAddition;
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand;
     this.operand1 = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.operand2 = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.rightSideSolution = this.operand1 + this.operand2;
     this.variable = getRandomVariableLetter(); 
     
     this.valueOfVariable = 0;
     if (0 == getRandomNumberInRange(0,1)){ this.valueOfVariable = this.operand1; this.operand1 = this.variable; }
     else{ this.valueOfVariable = this.operand2; this.operand2 = this.variable; }
  
     // public methods
     this.toString = getSimpleWordProblem;
     this.getWordProblem = getSimpleWordProblem;
     this.getNumberSentence = getSimpleNumberSentence;
     this.getIncorrectNumberSentence = getSimpleIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "simpleAdditionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function simpleSubtractionProblem() {
     switch(getRandomNumberInRange(1,3)){
        case 1: this.introText = "Difference between"; this.inBetweenText = "and"; break;
        case 2: this.introText = "Decreasing"; this.inBetweenText = "by"; break;
        case 3: this.introText = ""; this.inBetweenText = "minus"; break;
            default: alert("simpleSubtractionProblem: bad switch input");
     }
     this.operation = kSubtraction;
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand*2;   
     this.rightSideSolution = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.operand2 = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.operand1 = this.rightSideSolution + this.operand2;
     this.variable = getRandomVariableLetter(); 
     
     this.valueOfVariable = 0;
     if (0 == getRandomNumberInRange(0,1)){ this.valueOfVariable = this.operand1; this.operand1 = this.variable; }
     else{ this.valueOfVariable = this.operand2; this.operand2 = this.variable; }
  
     // public methods
     this.toString = getSimpleWordProblem;
     this.getWordProblem = getSimpleWordProblem;
     this.getNumberSentence = getSimpleNumberSentence;
     this.getIncorrectNumberSentence = getSimpleIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "simpleSubtractionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function simpleMultiplicationProblem() {
     switch(getRandomNumberInRange(1,3)){
        case 1: this.introText = "Multiplying"; this.inBetweenText = "and"; break;
        case 2: this.introText = "Product of"; this.inBetweenText = "and"; break;
        case 3: this.introText = ""; this.inBetweenText = "times"; break;
            default: alert("simpleMultiplicationProblem: bad switch input");
     }
     
     this.operation = kMultiplication;
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand; 
     this.operand1 = getRandomNumberInRange(1, kMaxOperand);
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.rightSideSolution = this.operand1 * this.operand2;
     this.variable = getRandomVariableLetter(); 
     
     this.valueOfVariable = this.operand2; this.operand2 = this.variable;
     
     // public methods
     this.toString = getSimpleWordProblem;
     this.getWordProblem = getSimpleWordProblem;
     this.getNumberSentence = getSimpleNumberSentence;
     this.getIncorrectNumberSentence = getSimpleIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "simpleMultiplicationProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function simpleDivisionProblem() {
     switch(getRandomNumberInRange(1,2)){
        case 1: this.introText = "Dividing"; this.inBetweenText = "by"; break;
        case 2: this.introText = "Quotient of"; this.inBetweenText = "and"; break;
            default: alert("simpleDivisionProblem: bad switch input");
     }
     this.operation = kDivision;
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand*kMaxOperand;    
     this.rightSideSolution = getRandomNumberInRange(1, kMaxOperand);
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.operand1 = this.rightSideSolution*this.operand2;
     this.variable = getRandomVariableLetter(); 
        
     this.valueOfVariable = 0;
     if (0 == getRandomNumberInRange(0,1)){ this.valueOfVariable = this.operand1; this.operand1 = this.variable; }
     else{ this.valueOfVariable = this.operand2; this.operand2 = this.variable; }
  
     // public methods
     this.toString = getSimpleWordProblem;
     this.getWordProblem = getSimpleWordProblem;
     this.getNumberSentence = getSimpleNumberSentence;
     this.getIncorrectNumberSentence = getSimpleIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "simpleDivisionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  // now lets do the complicated problems
  function getComplexWordProblem(){return (this.operand1 + " " + this.firstOperationText + " " + this.operand2 + " " + this.secondOperationText + " " + this.operand3 + " is " + this.rightSideSolution);}
  
  function getComplexIncorrectNumberSentence(){
     var temp = new complexIncorrectProblemCopier(this);
     return temp;
  }
  
  function complexIncorrectProblemCopier(complexProblem) {
     this.operation1 = getRandomOperation(); this.operation2 = getRandomOperation();
     while (this.operation1 == complexProblem.operation1) { this.operation1 = getRandomOperation(); }
     while (this.operation2 == complexProblem.operation2) { this.operation2 = getRandomOperation(); }
     
     this.operand2 = complexProblem.operand2;
     this.operand1 = complexProblem.operand1;
     this.operand3 = complexProblem.operand3;
     this.rightSideSolution = complexProblem.rightSideSolution;
     this.variable = complexProblem.variable; 
     this.valueOfVariable = complexProblem.valueOfVariable;
     
     function getComplexNumberSentence(){ 
        var numberSentence = ""+this.operand1;
            
            if (kMultiplication == this.operation1) numberSentence = numberSentence + this.operand2;
            else numberSentence = numberSentence + " " + this.operation1 + " " + this.operand2;
            
            return (numberSentence + " " + this.operation2 + " " + this.operand3 + " = " + this.rightSideSolution); 
     }
  
     // public methods
     this.toString = getComplexNumberSentence;
     this.getNumberSentence = getComplexNumberSentence;
     
     assert((this.valueOfVariable >= 0), "simpleDivisionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function addAndMultiplicationProblem() {
     this.firstOperationText = "times"; this.secondOperationText = "plus";
  
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand;
     this.operation1 = kMultiplication; this.operation2 = kAddition;
         
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.operand1 = getRandomNumberInRange(1, kMaxOperand);
     this.operand3 = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.rightSideSolution = this.operand1 * this.operand2 + this.operand3;
     this.variable = getRandomVariableLetter(); 
        
     this.valueOfVariable = this.operand2; this.operand2 = this.variable; 
  
     function getComplexNumberSentence(){ return (this.operand1 + this.operand2 + " + " + this.operand3 + " = " + this.rightSideSolution); }
  
     // public methods
     this.toString = getComplexWordProblem;
     this.getWordProblem = getComplexWordProblem;
     this.getNumberSentence = getComplexNumberSentence;
     this.getIncorrectNumberSentence = getComplexIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "addAndMultiplicationProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function subtractAndMultiplicationProblem() {
     this.firstOperationText = "times"; this.secondOperationText = "minus";
  
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand;
     this.operation1 = kMultiplication; this.operation2 = kSubtraction;
         
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.operand1 = getRandomNumberInRange(1, kMaxOperand);
     this.operand3 = getRandomNumberInRange(kMinOperand, this.operand1*this.operand2);
     this.rightSideSolution = this.operand1 * this.operand2 - this.operand3;
     this.variable = getRandomVariableLetter(); 
        
     this.valueOfVariable = this.operand2; this.operand2 = this.variable; 
  
     function getComplexNumberSentence(){ return (this.operand1 + this.operand2 + " - " + this.operand3 + " = " + this.rightSideSolution); }
  
     // public methods
     this.toString = getComplexWordProblem;
     this.getWordProblem = getComplexWordProblem;
     this.getNumberSentence = getComplexNumberSentence;
     this.getIncorrectNumberSentence = getComplexIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "subtractAndMultiplicationProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function addAndDivisionProblem() {
     this.firstOperationText = "divided by"; this.secondOperationText = "plus";
  
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand;
     this.operation1 = kDivision; this.operation2 = kAddition;
         
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.operand1 = getRandomNumberInRange(1, kMaxOperand)*this.operand2;
     this.operand3 = getRandomNumberInRange(kMinOperand, kMaxOperand);
     this.rightSideSolution = this.operand1/this.operand2 + this.operand3;
     this.variable = getRandomVariableLetter(); 
        
     this.valueOfVariable = this.operand1; this.operand1 = this.variable; 
  
     function getComplexNumberSentence(){ return (this.operand1 + " \367 " + this.operand2 + " + " + this.operand3 + " = " + this.rightSideSolution); }
  
     // public methods
     this.toString = getComplexWordProblem;
     this.getWordProblem = getComplexWordProblem;
     this.getNumberSentence = getComplexNumberSentence;
     this.getIncorrectNumberSentence = getComplexIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "addAndDivisionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  function subtractAndDivisionProblem() {
     this.firstOperationText = "divided by"; this.secondOperationText = "minus";
  
     this.kMinVariableValue = kMinOperand; this.kMaxVariableValue = kMaxOperand;
     this.operation1 = kDivision; this.operation2 = kSubtraction;
         
     this.operand2 = getRandomNumberInRange(1, kMaxOperand);
     this.operand1 = getRandomNumberInRange(1, kMaxOperand)*this.operand2;
     this.operand3 = getRandomNumberInRange(kMinOperand, this.operand1/this.operand2);
     this.rightSideSolution = this.operand1/this.operand2 - this.operand3;
     this.variable = getRandomVariableLetter(); 
        
     this.valueOfVariable = this.operand1; this.operand1 = this.variable; 
  
     function getComplexNumberSentence(){ return (this.operand1 + " \367 " + this.operand2 + " - " + this.operand3 + " = " + this.rightSideSolution); }
  
     // public methods
     this.toString = getComplexWordProblem;
     this.getWordProblem = getComplexWordProblem;
     this.getNumberSentence = getComplexNumberSentence;
     this.getIncorrectNumberSentence = getComplexIncorrectNumberSentence;
     this.getSolutionForVariable = getSolutionForVariable;
     this.getIncorrectSolutionForVariable = getIncorrectSolutionForVariable;
     
     assert((this.valueOfVariable >= 0), "subtractAndDivisionProblem(): valueOfVariable is too small: " + this.valueOfVariable);
  } 
  
  // test writing functions
  function requestPrintTest(){
     if (document.getElementById) {
        // clear all old dynamically created table stuff.            
        clearChildNodes("wordProblemTag");
        clearChildNodes("solution4Tag");
        clearChildNodes("solution3Tag");
        clearChildNodes("solution2Tag");
        clearChildNodes("solution1Tag");
        clearChildNodes("resultsTag");
                                                   
        // assure bug-free redraw in Gecko engine by letting window show cleared table
        if (navigator.product && navigator.product == "Gecko") {
           setTimeout("printTest()", 0);
        } 
        else {
               printTest();
        }
     }
     else {
        alert("Sorry, dynamic table feature works with IE5 or later for Windows, and Netscape 6 or later.");
     }  
  }
  
  function getNextProblem(){
     switch(getRandomNumberInRange(0,7)){
        case 0: return new simpleAdditionProblem(); break;
        case 1: return new simpleSubtractionProblem(); break;
        case 2: return new simpleMultiplicationProblem(); break;
        case 3: return new simpleDivisionProblem(); break;
        case 4: return new addAndMultiplicationProblem(); break;
        case 5: return new subtractAndMultiplicationProblem(); break;
        case 6: return new addAndDivisionProblem(); break;          
        case 7: return new subtractAndDivisionProblem(); break;          
        default: alert("getCurrentProblem(): bad switch value");
     }
  }
  
  function printTest(){
     gCurrentProblem = getNextProblem(); 
     // write the word problem
     writeTxtAtTDidOptions("wordProblemTag", gCurrentProblem, "+4", "black", false);
  
     // write the solutions to choose from
     switch(getRandomNumberInRange(0,3)){
        case 0:  
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintAskValueOfVariable();", "a) " + gCurrentProblem.getNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintIncorrectNumberSentence();", "b) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintIncorrectNumberSentence();", "c) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintIncorrectNumberSentence();", "d) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
               break;        
            case 1:
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintIncorrectNumberSentence();", "a) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintAskValueOfVariable();", "b) " + gCurrentProblem.getNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintIncorrectNumberSentence();", "c) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintIncorrectNumberSentence();", "d) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
               break;        
        case 2:
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintIncorrectNumberSentence();", "a) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintIncorrectNumberSentence();", "b) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintAskValueOfVariable();", "c) " + gCurrentProblem.getNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintIncorrectNumberSentence();", "d) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
               break;        
        case 3:
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintIncorrectNumberSentence();", "a) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintIncorrectNumberSentence();", "b) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintIncorrectNumberSentence();", "c) " + gCurrentProblem.getIncorrectNumberSentence(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintAskValueOfVariable();", "d) " + gCurrentProblem.getNumberSentence(), "+0", "brown", false, false);
               break;
        default: alert("printTest(): bad switch input");
     }
     
     writeTxtAtTDid("resultsTag", "Choose the correct number sentence for word problem!");
  }
  
  function requestPrintVariableValueResponse(isCorrect){
     if (document.getElementById) {
        // clear all old dynamically created table stuff.            
        clearChildNodes("resultsTag");
                                                   
        // assure bug-free redraw in Gecko engine by letting window show cleared table
        if (navigator.product && navigator.product == "Gecko") {
           setTimeout("printVariableValueResponse(" + isCorrect + ")", 0);
        } 
        else {
               printVariableValueResponse(isCorrect);
        }
     }
     else {
        alert("Sorry, dynamic table feature works with IE5 or later for Windows, and Netscape 6 or later.");
     }  
  }
  
  function printVariableValueResponse(isCorrect){
     if (isCorrect) 
        writeTxtAtTDid("resultsTag", "Very Good! You are so smart. " + gCurrentProblem.variable + " = " + gCurrentProblem.getSolutionForVariable());
     else           
        writeTxtAtTDid("resultsTag", "Incorrect, Find the value of " + gCurrentProblem.variable + " in " + gCurrentProblem.getNumberSentence() + "? Always check your work!");
  }
  
  function requestPrintIncorrectNumberSentence(){
     if (document.getElementById) {
        // clear all old dynamically created table stuff.            
        clearChildNodes("resultsTag");
                                                   
        // assure bug-free redraw in Gecko engine by letting window show cleared table
        if (navigator.product && navigator.product == "Gecko") {
           setTimeout("printIncorrectNumberSentence()", 0);
        } 
        else {
               printIncorrectNumberSentence();
        }
     }
     else {
        alert("Sorry, dynamic table feature works with IE5 or later for Windows, and Netscape 6 or later.");
     }  
  }
  
  function printIncorrectNumberSentence(){
     writeTxtAtTDid("resultsTag", "Incorrect, please choose again.");
  }
  
  function requestPrintAskValueOfVariable(){
     if (document.getElementById) {
        // clear all old dynamically created table stuff.            
        clearChildNodes("solution4Tag");
        clearChildNodes("solution3Tag");
        clearChildNodes("solution2Tag");
        clearChildNodes("solution1Tag");
        clearChildNodes("resultsTag");
                                                   
        // assure bug-free redraw in Gecko engine by letting window show cleared table
        if (navigator.product && navigator.product == "Gecko") {
           setTimeout("printAskValueOfVariable()", 0);
        } 
        else {
               printAskValueOfVariable();
        }
     }
     else {
        alert("Sorry, dynamic table feature works with IE5 or later for Windows, and Netscape 6 or later.");
     }  
  }
  
  function printAskValueOfVariable(){
     // write the solutions to choose from
     switch(getRandomNumberInRange(0,3)){
        case 0: 
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintVariableValueResponse(1);", "a) " + gCurrentProblem.getSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintVariableValueResponse(0);", "b) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintVariableValueResponse(0);", "c) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintVariableValueResponse(0);", "d) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
               break;
        case 1: 
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintVariableValueResponse(0);", "a) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintVariableValueResponse(1);", "b) " + gCurrentProblem.getSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintVariableValueResponse(0);", "c) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintVariableValueResponse(0);", "d) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
               break;
        case 2: 
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintVariableValueResponse(0);", "a) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintVariableValueResponse(0);", "b) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintVariableValueResponse(1);", "c) " + gCurrentProblem.getSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintVariableValueResponse(0);", "d) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
               break;
        case 3: 
           writeLinkAtTDidOptions("solution1Tag", "javascript:requestPrintVariableValueResponse(0);", "a) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution2Tag", "javascript:requestPrintVariableValueResponse(0);", "b) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution3Tag", "javascript:requestPrintVariableValueResponse(0);", "c) " + gCurrentProblem.getIncorrectSolutionForVariable(), "+0", "brown", false, false);
           writeLinkAtTDidOptions("solution4Tag", "javascript:requestPrintVariableValueResponse(1);", "d) " + gCurrentProblem.getSolutionForVariable(), "+0", "brown", false, false);
               break;
            default: alert("printTest(): bad switch input");
     }
     
     writeTxtAtTDid("resultsTag", "Correct, what is the value of " + gCurrentProblem.variable + " in " + gCurrentProblem.getNumberSentence() + "?");
  }
  
  // generates pop up window with guidance to solve word problems
  function requestHelp(){
     var generator=window.open('','name','height=400,width=700,scrollbars=1');
     
     generator.document.write('<html><head><title>Word Problems and Algebra</title></head><body>');   
     generator.document.write('<h1><b><center>Word Problems and Algebra</center></b></h1>');
     generator.document.write('<table align="center" border="1"><tr><td><b><font size="+2">+</font></b> plus, add, and, sum, total, increase</td></tr>');
     generator.document.write('<tr><td><b><font size="+2">-</font></b> minus, subtract, take away, difference, remains, decrease</td></tr>');
     generator.document.write('<tr><td><b><font size="+2">x</font></b> multiply, times, product, double (multiply by 2)</td></tr>');
     generator.document.write('<tr><td><b><font size="+2">\367</font></b> divide,  quotient, share, halve (divide by 2)</td></tr>');
     generator.document.write('<tr><td><b><font size="+2">=</font></b> equal to, is </td></tr></table><br>');
  
     generator.document.write('Read the word problems carefully so you can make a number sentence. ');
     generator.document.write('If you make a number sentence, then your work will be easy.');
     generator.document.write('<br>Examples:<br><b>Product of 6 and b is 42</b> means <b>6 x b = 6b = 42</b>');
     generator.document.write('<br><b>6 times c plus 8 is equal to 20</b> means <b>6c + 8 = 20</b><br>');
     
     generator.document.write('<h2><b><center>Balancing and Solving for Variables</center></b></h2>');   
     generator.document.write('To find what the variable equals, we want to use the opposite operation to get the variable by itself. <br>'); 
     generator.document.write('If you see adding, then subtract from both sides. <br>'); 
     generator.document.write('If you see subtraction, then add to both sides. <br>'); 
     generator.document.write('If you see multiplication, then divide from both sides. <br>'); 
     generator.document.write('If you see division, then multiply times both sides. <br>'); 
  
     generator.document.write('<br>Examples:<br>');
     generator.document.write('What is the value of <b>x plus 8 is 12</b>? x + 8 = 12<br>');
     generator.document.write('- is the opposite of + then x + 8 - 8 = 12 - 8 and then x + 0 = x = 4<br>');
     generator.document.write('So x = 4. <br><br>');
     
     generator.document.write('What is the value of b in <b>6b = 42</b>? 6b = 42 means 6 x b = 42.<br>');
     generator.document.write('\367 is the opposite of x.  6 \367 6 x b = 42 \367 6 then 1 x b = b = 42 \367 6 = 7<br>');
     generator.document.write('So b = 7.<br><br>');
     
     generator.document.write('Sometimes, there is more than one operation in your equation. ');
     generator.document.write('First, do the addition or subtraction first, then do division or multiplication to get the variable alone. ');
     
     generator.document.write('<br><br>Example:<br>');
     generator.document.write('6c + 8 = 20<br>');
     generator.document.write('6c + 8 - 8 = 20 - 8 Remember, balance the equation by working on both sides!<br>');
     generator.document.write('6c = 12<br>');
     generator.document.write('6 \367 6 x c = 12 \367 6<br>');
     generator.document.write('1 x c = c = 2<br>');
  
     generator.document.write('<br><br><b><center>Remember, ask your teacher if you do not understand.</center></b>');
     generator.document.write('<center><a href="javascript:self.close()">Close this window.</a></center>');
     generator.document.write('</body></html>');
     generator.document.close();
  }
  
  </script>
  </head>
  
  <body onload="javascript:requestPrintTest(); return false;">
  
  <table width="100%" valign="top" align="right" border="0">
     <tr>
        <td align="left"><font color="brown" size="+2"><b>Balance and Solve the Equation!</b></font></td>
        <td align="right">
           <a href="javascript:requestHelp();"><font size="-1" color="brown">Help Me!</font></a> |          
           <a href="javascript:myPop('Tested in IE6 and Safari');"><font size="-1" color="brown">About This Site</font></a> |
           <a href="mailto:aarontkennedy@gmail.com">;<font size="-1" color="brown">Suggestions</font></a>
        </td>      
     </tr>
  </table><br><br><br>
  
  <form name="balance">
     <table align="center" width="100%" border="0">
        <tr><td width="100%" colspan="4" align="center" id="wordProblemTag"></td></tr>
            
            <tr><td width="100%" colspan="4" align="center"><br></td></tr>
            
        <tr>
           <td width="25%" align="left" id="solution1Tag"></td>
           <td width="25%" align="left" id="solution2Tag"></td>
           <td width="25%" align="left" id="solution3Tag"></td>
           <td width="25%" align="left" id="solution4Tag"></td>
        </tr>
            
            <tr><td width="100%" colspan="4" align="center"><br></td></tr>          
            
            <tr><td width="100%" colspan="4" align="center" id="resultsTag"></td></tr>
            
            <tr>
               <td align="center" colspan="4">
                      <input name="nextQuestionButton" type="button" value="Give Me Another Question!" onClick="requestPrintTest();  return false;">
                   </td>
            </tr>
     </table>
  </form>
     
  </body>
  </html>
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _
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