Portable Calculator for Study Breaks
Complete a portable calculator for break time scenarios: includes real content, interactive controls, clear state feedback, and responsive layouts across sizes.
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<body data-aesthetic="editorial" data-composition="split-note">
<main class="page">
<header class="mast"><div><span class="eyebrow">editorial / Portable Calculator / INTERMEDIATE</span><h1>Portable Calculator for Study Breaks</h1><p class="intro">Complete a portable calculator for break time scenarios: includes real content, interactive controls, clear state feedback, and responsive layouts across sizes.</p></div><span class="scenario">Study Break</span></header>
<div class="composition-split"><aside class="split-note"><b>CASE 02</b><span>Master the semantic structure, responsive layout, keyboard interaction, and state synchronization of a portable calculator.</span></aside><section class="demo" aria-label="Study Break Portable Calculator Interaction Area"><div class="workflow-session"><header class="session-command"><div><span class="eyebrow">Study Break SESSION</span><h2>Study Break Timer Console</h2></div><output id="workflowSessionClock">00:45</output><label>Round Duration<input id="workflowSessionLength" type="range" min="15" max="90" step="15" value="45"><span>sec</span></label><button id="workflowSessionToggle" class="action primary" type="button">Start Break</button></header><div id="workflowSessionProgress" role="progressbar" aria-label="Study Break Timer Progress" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0"><i></i></div><section id="workflowCore" class="workflow-core session-stage" data-session-phase="ready" tabindex="-1"><!-- 11DZ_CORE_START:mini-apps-games-calculator-pad --><div class="calc-workbench"><div class="mini calculator"><output id="calcDisplay" aria-live="polite">0</output><div class="calc-keys"><button type="button" data-key="7" data-core-bridge="mini-apps-games-calculator-pad">7</button><button type="button" data-key="8">8</button><button type="button" data-key="9">9</button><button type="button" data-key="÷">÷</button><button type="button" data-key="4">4</button><button type="button" data-key="5">5</button><button type="button" data-key="6">6</button><button type="button" data-key="×">×</button><button type="button" data-key="1">1</button><button type="button" data-key="2">2</button><button type="button" data-key="3">3</button><button type="button" data-key="−">−</button><button type="button" data-key="0">0</button><button type="button" data-key=".">.</button><button type="button" data-key="=">=</button><button type="button" data-key="＋">＋</button></div><button id="calcClear" class="action" type="button">Clear</button></div><aside class="calc-ledger"><span class="eyebrow">Class Break MEMO</span><h2>Study break calculator memo</h2><ul><li>Class break collaboration</li><li>Break-time progress</li><li>Class Break Reminder</li><li>Recess favorites</li><li>Study Break Overview</li><li>Recess plan</li></ul><p>The number keys, operators, and equals sign are handled by an explicit state machine.</p></aside></div><!-- 11DZ_CORE_END --></section><footer class="session-log"><strong id="workflowSessionScore">0 interaction checkpoints</strong><ol id="workflowSessionLaps" aria-label="Round Log"></ol></footer></div><p id="status" class="status" role="status" aria-live="polite"></p></section></div>
</main>
<script>
'use strict';
const statusOutput = document.querySelector('#status');
const announce = message => { statusOutput.textContent = message; };
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let current='0';let accumulator=null;let pendingOperator=null;let replaceCurrent=false;const display=document.querySelector('#calcDisplay');const calculator=document.querySelector('.calculator');const operations={'＋':(left,right)=>left+right,'−':(left,right)=>left-right,'×':(left,right)=>left*right,'÷':(left,right)=>right===0?NaN:left/right};function renderCalculator(){display.textContent=current;}function resetCalculator(){current='0';accumulator=null;pendingOperator=null;replaceCurrent=false;renderCalculator();}function calculatePending(){if(pendingOperator===null||accumulator===null)return Number(current);const result=operations[pendingOperator](accumulator,Number(current));if(!Number.isFinite(result)){current='Error';accumulator=null;pendingOperator=null;replaceCurrent=true;return null;}current=String(Number(result.toFixed(10)));accumulator=Number(current);return accumulator;}function pressCalculatorKey(key){if(/^\d$/.test(key)){if(current==='Error'||replaceCurrent){current=key;replaceCurrent=false;}else if(current==='0')current=key;else current+=key;}else if(key==='.'){if(current==='Error'||replaceCurrent){current='0.';replaceCurrent=false;}else if(!current.includes('.'))current+='.';}else if(key in operations){if(current==='Error')resetCalculator();if(pendingOperator!==null&&!replaceCurrent)calculatePending();accumulator=Number(current);pendingOperator=key;replaceCurrent=true;}else if(key==='='){if(pendingOperator!==null&&calculatePending()!==null){pendingOperator=null;replaceCurrent=true;}}renderCalculator();announce(current==='Error'?'Unable to complete the calculation':'Calculation Result '+current);}document.querySelectorAll('[data-key]').forEach(button=>button.addEventListener('click',()=>pressCalculatorKey(button.dataset.key)));document.querySelector('#calcClear').addEventListener('click',()=>{resetCalculator();announce('Cleared');});document.addEventListener('keydown',event=>{if(!calculator.contains(document.activeElement))return;const keyboardMap={Enter:'=',Escape:'Clear','+':'＋','-':'−','*':'×','/':'÷'};const key=keyboardMap[event.key]||event.key;if(key==='Clear'){event.preventDefault();resetCalculator();announce('Cleared');return;}if(/^\d$/.test(key)||['.','=','＋','−','×','÷'].includes(key)){event.preventDefault();pressCalculatorKey(key);}});
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workflowBridgeReset();
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