Long Division (3-digit ÷ 1-digit)

How to do long division (3-digit ÷ 1-digit)

Long division follows a repeating four-step cycle: Divide, Multiply, Subtract, Bring down. You work from the left-most digit of the number being divided (the dividend) towards the right. Use the animation above to watch each cycle for 20 problems, then follow the written method.

The method — the D-M-S-B cycle

1. Divide: how many times does the divisor go into the current number? Write that digit in the quotient (on top).
2. Multiply: multiply that quotient digit by the divisor and write the product underneath.
3. Subtract: subtract the product to get the remainder for this step.
4. Bring down: bring down the next digit of the dividend next to the remainder, and repeat the cycle.
5. When there are no digits left to bring down, whatever is left is the remainder.

Worked example: 936 ÷ 4

Step	Divide / Multiply / Subtract	Bring down
1	9 ÷ 4 = 2 (write 2); 2 × 4 = 8; 9 − 8 = 1	bring down 3 → 13
2	13 ÷ 4 = 3 (write 3); 3 × 4 = 12; 13 − 12 = 1	bring down 6 → 16
3	16 ÷ 4 = 4 (write 4); 4 × 4 = 16; 16 − 16 = 0	no more digits

So 936 ÷ 4 = 234 (remainder 0).

Common mistakes to avoid

• Forgetting a zero in the quotient when the divisor doesn't go into a brought-down number — you must still write a 0 and bring down the next digit.
• Bringing down before subtracting — always subtract first, then bring down.
• Misaligning the columns, which makes the subtraction wrong.
• Ignoring the remainder at the end.

Practice problems

Try these in the animation above: 848 ÷ 4, 762 ÷ 6, 984 ÷ 8, 618 ÷ 6 (note the middle zero), 728 ÷ 7, 855 ÷ 5.

Quick tip

Say the cycle out loud each time — “Divide, Multiply, Subtract, Bring down” — until it becomes automatic. Every long-division problem is just that cycle repeated once per digit.