Standard arithmetic calculator with history tracking. Perform addition, subtraction, multiplication, and division with a clean, intuitive interface.
A calculator is a device or application that performs arithmetic operations on numbers. The most basic calculators support four fundamental operations: addition (+), subtraction (−), multiplication (×), and division (÷). This calculator uses standard infix notation, where operators appear between operands (e.g., 5 + 3), which is the most intuitive form for human users. When you enter a calculation, the system follows the order of operations internally, though this simple calculator processes operations sequentially as they're entered.
The calculator maintains a state machine with four key pieces of information: the current display value, the previous operand, the selected operation, and a "fresh" flag indicating whether the next digit should start a new number or append to the current one. When you press an operator button (+, −, ×, ÷), the calculator stores the current display value and waits for the second operand. Pressing "=" triggers the computation using the stored operator and both operands, displaying the result and adding the complete expression to the history log. Additional features include percentage conversion (divides by 100), sign toggling (±), backspace (⌫), and clear (C) functions. The calculator prevents common errors like division by zero (returns "Error") and limits precision to 12 significant figures to avoid floating-point display issues.
Click the digit buttons (0-9) to enter your first number. Use the decimal point (.) for non-integer values. The display shows your input in real-time.
Click one of the four operator buttons: + (addition), − (subtraction), × (multiplication), or ÷ (division). The calculator stores your first number and the operation.
Enter your second operand using the digit buttons. The top line of the display shows your pending operation (e.g., "25 +") as a reminder.
Press the = button to compute the result. The answer appears on the display, and the complete calculation is logged in the History panel on the right.
C clears everything and resets to 0. ⌫ (backspace) deletes the last digit. ± toggles between positive and negative. % converts the display value to a percentage (divides by 100). The History panel keeps your last 10 calculations.
Calculating a Restaurant Bill Split
Each person pays $51.00, which includes their share of the meal plus the 20% tip.
The % button converts the current display value to a percentage by dividing it by 100. For example, pressing 20 then % gives you 0.2 (which is 20%).
The calculator displays 'Error' when you attempt to divide by zero, which is mathematically undefined. Check that your second number (divisor) is not zero.
The history panel stores your last 10 calculations. Older entries are automatically removed when new calculations are added. You can clear the history at any time using the 'Clear history' button.
C (Clear) resets the entire calculator to zero, erasing all stored values and the current operation. ⌫ (Backspace) only deletes the last digit of the current number, allowing you to correct typos.
This calculator processes operations sequentially. After pressing =, you can use the result as the starting point for a new calculation. For complex expressions with multiple operations, you'll need to calculate intermediate results.
Computers use binary floating-point arithmetic, which can sometimes produce tiny rounding errors (e.g., 0.1 + 0.2 = 0.30000000000000004). This calculator limits precision to 12 significant figures to minimize display issues.
The ± (plus-minus) button toggles the sign of the current display value between positive and negative. If the display shows 42, pressing ± changes it to -42, and vice versa.
No, this is a simple sequential calculator that processes operations as they're entered, from left to right. For expressions requiring proper order of operations, calculate sub-expressions first and use the results.