Python: doing maths with operators

Computers are brilliant calculators. Python has operators for adding and multiplying, and some special ones for whole-number division and remainders.

Practise this lesson free (7 questions)

Arithmetic operators

Python uses * for multiply and / for divide, not × and ÷.
OperatorMeaningExampleResult
+add7 + 310
-subtract7 - 34
*multiply7 * 321
/divide7 / 23.5
//whole-number division (quotient)17 // 53
%remainder (modulus)17 % 52
**power2 ** 38

Order of operations

Python follows the same order as maths: brackets first, then powers, then multiply and divide, then add and subtract.
print(2 + 3 * 4)
print((2 + 3) * 4)
Output:
14
20
In the first line 3 * 4 is done first. Brackets change the order.

Why // and % are useful

sweets = 23
people = 4
print(sweets // people)
print(sweets % people)
Output:
5
3
23 sweets shared between 4 people: each gets 5, with 3 left over.
% is also handy for testing whether a number is even: n % 2 is 0 for even numbers.
Note: / always gives a decimal answer in Python, so 8 / 2 gives 4.0.
Worked example

What does this print?
minutes = 135
print(minutes // 60)
print(minutes % 60)

  1. 135 // 60: 60 goes into 135 twice, so 2.
  2. 135 % 60: the remainder is 135 - 120 = 15.
  3. So 135 minutes is 2 hours 15 minutes.

Answer: 2 then 15

Key idea

Python uses + - * / for basic maths, // for whole-number division, % for the remainder and ** for powers. Brackets are worked out first, then powers, then * and /, then + and -.

Key words
AND
A Boolean operator that gives True (1) only when both inputs are True.
Output
Information sent out from a computer, for example to a screen, speaker or printer.

All KS3 Computing key terms and definitions →

Quick check

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Extra practice

2 more questions

Try each one, then tap to check.

  1. What does this print?
    print(23 // 5)

    Show the answer

    Answer: 4

    23 ÷ 5 = 4 remainder 3. // keeps the whole number: 4.

  2. What does this print?
    print(23 % 5)

    Show the answer

    Answer: 3

    23 ÷ 5 = 4 remainder 3. % gives the remainder: 3.

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Sources and references

Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.