← Back to Math Adventures

Long Division

Overview

Does McDonald's Sell Cheese Burgers?

What is it?

The step-by-step process for dividing large numbers.

History

The notation we use today was popularized in the 1700s.

Key Idea

DMSCB: Divide, Multiply, Subtract, Check, Bring down.

Practice This Topic

Concept Guide

Plain English: When numbers are too big to divide mentally, we break them into chunks. We divide the Hundreds, then the Tens, then the Ones. It's a loop you repeat until you run out of numbers.

Real-world example: Calculating miles per gallon on a road trip (450 miles / 12 gallons).

How to do it

  1. Divide (How many times does it fit?)
  2. Multiply (Number on top x Divisor)
  3. Subtract (Remainder)
  4. Check (Is remainder smaller than divisor?)
  5. Bring Down (Next digit)

Common Pitfall

Forgetting to 'Bring Down' the next number after subtracting.

Word Problem
"A lottery prize of $840 is split among 4 winners."
Reasoning: 840 รท 4. 4 into 8 is 2. 4 into 4 is 1. 4 into 0 is 0. Each gets $210.

Practice Examples

The Setup
21 ___ 4| 84 -8 -- 04 -4 0
Zero remainder. Perfect division.