| Mistake | What happens | Fix | |---------|--------------|-----| | Pressing = after each operation | 3+4= shows 7, then pressing *2 multiplies 7*2 | Just keep typing operators without = until the end | | Using % after + or - incorrectly | 100 + 50 % = 150 (correct), but 100 + 50 % + 20 = 170? No: 100 + 50 % = → 150, then +20 = 170 | Clear with CE between different percent contexts | | Memory not cleared | Old subtotal still inside MR | Press MC before starting new calculation | | Typing 00 when you meant 0 | 100 vs 10000 | Use backspace |

Calcsimple is perfect for:

function inputDigit(d) /* handle overflow, leading zero */ function inputOperation(op) if (!waitingForOperand) calculate(); lastOp = op; waitingForOperand = true;