// Numbas version: exam_results_page_options
{"name": "Fractions: adding and subtracting, numerical, already with common denominator", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Fractions: adding and subtracting, numerical, already with common denominator", "tags": [], "metadata": {"description": "<p>Fractions already have a common denominator. Addition and subtraction 50:50 split, when subtracting, the answer is negative half the time. Students shouldn't have to worry about reducing fractions by design.</p>", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "statement": "<p>Express the following as a single fraction (using / as the fraction bar).</p>", "advice": "<p>Since both denominators are the same, i.e. $\\var{den}$. We can simply <span data-jme-visible=\"addSub=1\">add</span><span data-jme-visible=\"addSub=-1\">subtract</span> the numerators, $\\var{num1}$ and $\\var{num2}$, and put that over the common denominator.</p>\n<p><span data-jme-visible=\"addSub=1\">$\\begin{align*}\\dfrac{\\var{num1}}{\\var{den}}+\\dfrac{\\var{num2}}{\\var{den}}&amp;=\\dfrac{\\var{num1}+\\var{num2}}{\\var{den}}\\\\[3pt]&amp;=\\dfrac{\\var{ansNum}}{\\var{den}}\\end{align*}$</span></p>\n<p><span data-jme-visible=\"addSub=-1\">$\\begin{align*}\\dfrac{\\var{num1}}{\\var{den}}-\\dfrac{\\var{num2}}{\\var{den}}&amp;=\\dfrac{\\var{num1}-\\var{num2}}{\\var{den}}\\\\[3pt]&amp;=\\dfrac{\\var{ansNum}}{\\var{den}}\\end{align*}$</span></p>\n<p></p>", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"den": {"name": "den", "group": "Ungrouped variables", "definition": "numbers[2]", "description": "", "templateType": "anything", "can_override": false}, "num1": {"name": "num1", "group": "Ungrouped variables", "definition": "numbers[0]", "description": "", "templateType": "anything", "can_override": false}, "num2": {"name": "num2", "group": "Ungrouped variables", "definition": "numbers[1]", "description": "", "templateType": "anything", "can_override": false}, "addSub": {"name": "addSub", "group": "Ungrouped variables", "definition": "random(-1,1)", "description": "<p>adding or subtracting</p>", "templateType": "anything", "can_override": false}, "ansnum": {"name": "ansnum", "group": "Ungrouped variables", "definition": "if(addSub=1,num1+num2,num1-num2)", "description": "", "templateType": "anything", "can_override": false}, "numbers": {"name": "numbers", "group": "Ungrouped variables", "definition": "random(tempnumbers,[tempnumbers[1],tempnumbers[0],tempnumbers[2]])", "description": "", "templateType": "anything", "can_override": false}, "tempnumbers": {"name": "tempnumbers", "group": "Ungrouped variables", "definition": "sort(shuffle([3,5,7,11,13,17,19,23,29])[0..3])", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["tempnumbers", "numbers", "den", "num1", "num2", "addSub", "ansnum"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "gapfill", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p><span data-jme-visible=\"addSub=1\">$\\dfrac{\\var{num1}}{\\var{den}}+\\dfrac{\\var{num2}}{\\var{den}}$</span> <span data-jme-visible=\"addSub=-1\">$\\dfrac{\\var{num1}}{\\var{den}}-\\dfrac{\\var{num2}}{\\var{den}}$</span>&nbsp; $=$ [[0]]</p>", "gaps": [{"type": "numberentry", "useCustomName": false, "customName": "", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "ansNum/den", "maxValue": "ansNum/den", "correctAnswerFraction": true, "allowFractions": true, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}]}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}