Long division, step by step

Long division splits a big number into equal groups. It uses the same four steps over and over: Divide, Multiply, Subtract, Bring down.

Example: 156 ÷ 4

1. Divide: 4 doesn't go into 1, so look at 15. 4 goes into 15 three times (4 × 3 = 12). Write 3 on top.
2. Multiply: 3 × 4 = 12. Write 12 under the 15.
3. Subtract: 15 − 12 = 3.
4. Bring down: bring down the 6 to make 36.
5. Repeat: 4 goes into 36 nine times (4 × 9 = 36). Write 9 on top. 36 − 36 = 0.

What if there's a remainder?

If something is left over at the end, that's the remainder. For example, 157 ÷ 4 = 39 remainder 1, because 39 × 4 = 156 and 157 − 156 = 1.

Try one yourself

Common mistakes

• Forgetting to write a 0 on top when the divisor doesn't fit into the number you brought down.
• Subtracting wrong. Double-check each subtraction before you bring down.
• Not checking: multiply your answer by the divisor (and add the remainder) to make sure it matches.