# Add two 3-digit numbers

## Learning focus

In this lesson, you will learn how to add two three-digit numbers together.

This lesson includes:

- one quiz
- one learning summary
- one video
- two practise activities

# Quiz

Check your knowledge of adding two 3-digit numbers together in this quiz. Get your pen and paper handy and try using the column method.

# Learn

First, let’s find out a bit about the method for adding numbers together using number columns. Watch this short animation featuring a hive of helpful bees from KS2 Maths.

## Checklist

There are a few things you should always do when adding large numbers together:

- When writing down sums,
**separate the numbers into ones, tens and hundreds.**List the numbers in a column and always start adding with the ones first. **Estimate first and check afterwards**- it's a good idea to estimate a rough answer first and then check your actual answer.**Order doesn't matter**- remember that 345 + 129 is the same as 129 + 345.**Key words**- look out for these words in problems: total, sum, altogether, more. They all indicate an addition calculation.

## Column addition

Numbers can be added together using the column method which involves writing one number underneath the other.

## Example 1

**What is 343 + 315?**

## Example 2

**What is 343 + 329?**

If the two numbers in a place value column add up to a number greater than 9, you must carry a digit.

## Example 3

**One apple tree has 178 apples. Another has 253 apples. How many apples are there altogether?**

You can use the column method to solve this problem.

# Practise

## Activity 1

**Hive maths**

Click on the image below to see if you can add the numbers correctly.

## Activity 2

On a piece of paper, and using the column method, try to work out the following:

**258 + 351****541 + 639****745 + 362**

# Play

Play **Guardians: Defenders of Mathematica** to learn more and sharpen your skills on this topic.

# There's more to learn

Have a look at these other resources.