I want the last 3 operations in localStorage , tell plc how to do it correctly

 ////////////////take buttons value//////////////////////// let numbers = document.querySelectorAll('.number'), operations = document.querySelectorAll('.operator'), out = document.getElementById('cancel'), disp = document.getElementById('display'), memoryCurrentNumber = 0, memoryNewNumber = false, memoryPendingOperation = ''; //////////////////////////////////////take numbers content/////////////// for(let i=0; i<numbers.length; i++) { let number = numbers[i]; number.addEventListener('click', e =>{ numberPress(e.target.textContent); window.localStorage.setItem('key','number'); }); } //////////////////////////////////////take number operators content/////////////// for(let i=0; i<operations.length; i++) { let operationBtn = operations[i]; operationBtn.addEventListener('click', e =>{ operation(e.target.textContent); window.localStorage.setItem('key','operator'); }); } ///////////////////////////button cancel, clear all field/////////////////// out.addEventListener('click', e =>{ disp.value = '0'; memoryNewNumber = true; memoryCurrentNumber = 0; memoryPendingOperation = ''; }); ////////////////////////////////////write numbers and fix position zero////////////////// let numberPress = (number) => { if(memoryNewNumber) { disp.value = number; memoryNewNumber = false; }else { if(disp.value === '0') { disp.value = number; }else { disp.value += number; } } window.localStorage.getItem("key"); }; //////////////////////general calc operations//////////////////////// let operation = (operation) => { let localOperationMemory = disp.value; if (memoryNewNumber && memoryPendingOperation !== '=') { /////////////// make '=' res disp.value = memoryCurrentNumber; }else { memoryNewNumber = true; if(memoryPendingOperation === '+') { memoryCurrentNumber += parseFloat(localOperationMemory); } else if(memoryPendingOperation === '-') { memoryCurrentNumber -= parseFloat(localOperationMemory); }else if(memoryPendingOperation === '*') { memoryCurrentNumber *= parseFloat(localOperationMemory); }else if(memoryPendingOperation === '/') { memoryCurrentNumber /= parseFloat(localOperationMemory); if(localOperationMemory == 0) { memoryCurrentNumber = 'calculator smart u no :('; memoryNewNumber = true; memoryPendingOperation = ''; } } else { memoryCurrentNumber = parseFloat(localOperationMemory); } disp.value = memoryCurrentNumber; memoryPendingOperation = operation; } window.localStorage.getItem("key"); }; 
 <div class="col-lg-12 calculator"> <div class="display"> <input disabled type="text" id="display" value="0"> </div> <div class="keybord"> <button class="number">1</button> <button class="number">2</button> <button class="number">3</button> <button class="operator" id="plus">+</button> <br> <button class="number">4</button> <button class="number">5</button> <button class="number">6</button> <button class="operator">-</button> <br> <button class="number">7</button> <button class="number">8</button> <button class="number">9</button> <button class="operator" id="multiply">*</button> <br> <button class="number">0</button> <button id="res" class="operator">=</button> <button id="cancel">c</button> <button class="operator" id="sr">/</button> </div> </div>

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