Basic Calculator
Basic calculator for + − × ÷ in the standard order of operations (2 + 3 × 4 = 14), with % and memory keys, ^ for powers and the result as a fraction. How it works
Use the Basic Calculator
About the Basic Calculator
2 + 3 × 4 = 14: the calculator follows the standard order of operations, powers first, then multiplication and division, then addition and subtraction, where a calculator that works strictly left to right would give 20. The display is rounded to 9 decimal places, so 1 ÷ 3 reads 0.333333333, and a result that is not a whole number also opens a panel with its fraction, such as 5/2 for 2.5.
Order of operations and rounding: what the display shows
| Keys | Display | Why |
|---|---|---|
| 2 + 3 × 4 | 14 | Multiplication comes before addition. |
| 2 ^ 3 ^ 2 | 512 | Powers group from the right, so this is 2 ^ 9. |
| 2 × -3 | -6 | A minus pressed right after an operator starts a negative number. |
| 0.1 + 0.2 | 0.3 | The stored sum is 0.30000000000000004; the display rounds to 9 decimal places. |
| 1 ÷ 3 | 0.333333333 | Rounded to 9 decimal places. |
| 1 ÷ 0 | Error | The message Cannot divide by zero replaces the result. |
Keys are as typed on the keyboard or keypad, with Enter or = at the end.
The Result Formats panel for results that open it
| Calculation | Display | Fraction | Scientific | Grouped | Binary |
|---|---|---|---|---|---|
| 10 ÷ 4 | 2.5 | 5/2 | none | none | none |
| 0.5 + 0.25 | 0.75 | 3/4 | none | none | none |
| 20 ÷ 3 | 6.666666667 | 20/3 | none | none | none |
| 2 ^ 40 | 1099511627776 | none | 1.099512e+12 | 1,099,511,627,776 | 10000000000000000000000000000000000000000 |
| 1,234,567 × 8,901 | 10988880867 | none | 1.098888e+10 | 10,988,880,867 | 1010001110111111010000001111100011 |
The panel opens under the display when the result is not a whole number or is 10,000,000,000 or more. None means that format is not offered for that result: Scientific appears from 10,000,000,000 up, Grouped from 1,000 and Binary for whole numbers. The panel also lists a Decimal row, to 10 decimal places, so it can show one digit more than the display: 6.6666666667 for 20 ÷ 3.
How to use this tool
- Press the keys or type on a keyboard: digits, the decimal point and the operators + - × ÷, or ^ for a power.
- Press = or Enter. The whole expression is worked out at once, so you can chain several operations before pressing it.
- When the answer is not a whole number or is 10,000,000,000 or more, the Result Formats panel opens under the display. Click a value in it to copy that form.
- For a percent, press % after the second number: 200 + 10 % = 220 adds 10% of 200, and 50 × 10 % = 5. M+ and M- add the display to the memory or take it away, MR recalls it and MC empties it.
Frequently asked questions
- Does the calculator follow the order of operations?
- Yes. 2 + 3 × 4 shows 14 because the multiplication is done first; (2 + 3) × 4 would be 20. Powers come before multiplication, and ^ groups from the right, so 2 ^ 3 ^ 2 is 2 ^ 9 = 512. The keypad has no parentheses, so to add first, press = after 2 + 3 and continue from the answer: 5 × 4 = 20.
- How do I enter a negative number?
- Press the minus key right after an operator: 2 × -3 = -6. There is no sign-change key. A minus on its own is not a value, so = and the operators wait until a digit follows it.
- Why does 0.1 + 0.2 show 0.3?
- Computers store 0.1 and 0.2 in binary, which cannot hold them exactly, so the raw sum is 0.30000000000000004. The calculator rounds the display to 9 decimal places, which gives 0.3, and 1 ÷ 3 shows 0.333333333.
- How do I turn a decimal into a fraction on this calculator?
- Enter the calculation and press =. A result that is not a whole number opens the Result Formats panel with its fraction: 2.5 is 5/2, 0.75 is 3/4 and 20 ÷ 3 is 20/3. A fraction is shown only when it matches the 9 decimals on the display, with a denominator up to 1,000,000, so 0.3333333 typed in gets no 1/3. For a decimal you already have, the Decimal to Fraction Calculator on this site takes it directly.
- What happens when I divide by zero?
- The display shows Error and a message reads Cannot divide by zero. A result too big for a number, such as 10 ^ 400, shows Result is too large to display. Press AC to start again.
- Which keyboard keys work?
- Digits and the decimal point; + - * (or x) and / for the operators; ^ for a power; Enter or = for the result; Backspace to delete a digit; Esc or c to clear. The % key and the memory keys MC, MR, M+ and M- are on the keypad only. Keys typed into another field or a dialog on the page are not taken by the calculator.
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