Answer, order and session history
The answer uses your selected decimal places when rounding is needed. Calculate or press Enter to add a successful calculation to this page’s history. Memory and history are session-only and reset when you reload the page.
For exact signed whole-number arithmetic with individual working steps, use the Integer Calculator .
The formula
Both modes respect explicit parentheses. Standard mode performs multiplication and division before addition and subtraction. Left-to-right mode evaluates the four binary operations in sequence within each parenthesized group. Decimal arithmetic avoids common binary decimal artifacts.
The same keys with two evaluation conventions
Enter 12.5 + 7.5 * 2. Standard order gives 27.5 because multiplication occurs first. Switch to Left to right to get 40. The evaluation-order card explains which convention produced the answer.
How to use this calculator
- Type a calculation or use the number and operation buttons.
- Choose Standard order or Left to right before calculating.
- Press =, Enter or Calculate to save a successful result to history. Press an operator next to continue from that answer, or a number to start a new calculation.
- Use Ans to insert the current answer; use M+, M−, MR and MC for memory.
A keypad for ordinary arithmetic
Four functions cover addition, subtraction, multiplication and division. A decimal point lets you calculate amounts such as prices and measurements. Parentheses keep grouping visible, and a minus sign permits negative inputs. The expression remains editable so correcting one digit does not require starting again.
Backspace removes the preceding character at the caret or the selected text. Clear entry empties the expression, while Reset restores the worked example and clears this session’s history and memory. On a keyboard, Enter calculates and Escape clears the entry. Other ordinary editing shortcuts remain available.
Using stored answers deliberately
Ans inserts the current valid displayed answer in parentheses, which protects a negative answer when used in another expression. Memory stores a separate total: M+ adds the current answer, M− subtracts it, MR recalls it and MC clears it. The visible memory status keeps that value distinct from the main answer.
History records up to twenty successful submitted calculations with their evaluation order. Choose a history item to restore its expression and order. Live updates help while editing, but incomplete or invalid expressions are not added to history. Copy transfers the displayed answer, including any chosen rounding.
Assumptions & limitations
What this calculation assumes
- A period separates decimal places, and all four operations use real numeric values.
- The chosen order is applied consistently within explicit parentheses.
What to keep in mind
- Expressions are limited to 1,200 characters, 200 tokens and 100 characters per numeric literal. Output is bounded to 1,000 decimal positions.
- Percentage shortcuts, roots, scientific notation, powers and exam certification are outside this four-function interface.
Common questions
Why does 2 + 3 * 4 sometimes give 20?
A desk calculator may calculate left to right. Choose that mode for 20, or Standard order for 14. The chosen mode is shown with the answer.
Does Reset clear memory?
Yes. Reset restores the example and clears memory and calculation history. Clear entry affects only the expression.
Can I copy an answer with many decimals?
Yes. Open Advanced settings to choose up to fifty decimal places, calculate, then use Copy answer. Repeating quotients are rounded.
Sources & further reading
Reviewed on