Basic Calculator
Add, subtract, multiply and divide on the keypad, then press = for the result. You can type a whole sum before pressing =. The calculator works out × and ÷ before + and −, so 2 + 3 × 4 gives 14. Use the ( and ) keys to change that order: (2 + 3) × 4 gives 20. The % key gives the remainder of a division, so 17 % 5 = 2. Results are rounded to 10 decimal places, which makes 1 ÷ 3 show 0.3333333333. A division by zero shows Error.
How to use the Basic Calculator
- Type your calculation on the keypad of the Basic Calculator above.
- Press = to see the result.
- Press C to clear the display and start a new calculation.
Order of operations
( ) first, inside out · · · then × ÷ %, left to right · · · then + −, left to right
The calculator works out each pair of parentheses first, the innermost pair before the others. Within each level it works from left to right. 100 ÷ 4 ÷ 5 = 5, because 100 ÷ 4 = 25 comes first and 25 ÷ 5 = 5 after it. Parentheses change that: 100 ÷ (4 ÷ 5) = 125.
Worked example
15 + 6 × 2 = 27, because 6 × 2 = 12 comes first and 15 + 12 = 27. To add first, press ( 15 + 6 ) × 2 =. When you press ), the display shows 21, the value of the group. Then × 2 = gives 42. A digit typed straight after a result starts a new number.
Frequently asked questions
Why is 2 + 3 × 4 equal to 14, not 20?
Multiplication comes before addition. 3 × 4 = 12 first, then 2 + 12 = 14. To get 20, use parentheses: (2 + 3) × 4 = 20.
How do parentheses work on this calculator?
Press ( to open a group and ) to close it. Groups can sit inside each other: ((1 + 2) × 3 + 1) × 2 = 20. A number right next to a group multiplies it, so 2(3 + 4) = 14 and (3 + 4)2 = 14. Pressing = closes any group still open, so (2 + 3 = gives 5. Inside parentheses the calculator uses exact fractions, so 1 ÷ (0.3 − 0.1 − 0.2) shows Error, because that group is exactly 0.
How do I multiply by a negative number?
Put it in parentheses and press − first: 2 × ( − 3 ) = gives −6. Without the parentheses, a second operator replaces the first, so 2 × − 3 = reads as 2 − 3 and gives −1.
What does the % key do?
It gives the remainder after a division. 17 % 5 = 2, because 5 goes into 17 three times with 2 left over. It does not work out percentages. For 25% of 80, multiply and divide instead: 80 × 25 ÷ 100 = 20. The percentage calculator has modes for this.
Can I do square roots or powers?
No. The keypad has the four operations, parentheses and the remainder key. The scientific calculator has square roots, powers, trig and logs.