Long Division

Lesson 2 of 10Grades 4–5

Division is the opposite of multiplication. Long division lets you divide large numbers by breaking the problem into smaller steps: Divide, Multiply, Subtract, Bring Down — repeat. It's a systematic process anyone can master.

Key Concepts

DMSB — The Four Steps

Divide: how many times does the divisor go into the current number? Multiply: divisor × your answer. Subtract: remove that amount. Bring Down: pull down the next digit. Repeat until you run out of digits. The remainder (if any) is what's left over.

Remainders

Sometimes a number does not divide evenly. The remainder is written as R followed by the leftover value. 17 ÷ 5 = 3 R 2 (because 5×3=15, and 17-15=2). Remainders matter in real problems: if 17 students need groups of 5, you get 3 full groups with 2 left over.

Dividing by Two-Digit Numbers

When dividing by a two-digit number like 23, you estimate: how many times does 23 go into 92? Try 4: 23×4=92. Exact! If you overshoot (product is too big), try one less. If you undershoot, try one more. Estimation is key.

🆕 Division Step-by-Step

Enter a dividend and divisor to see every step of long division.

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✅ Check Your Understanding

1. What do the letters DMSB stand for?

2. What is the remainder of 29 ÷ 4?

3. If 50 students need buses of 12, how many buses are needed?