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Partitioning for addition

addition

Partitioning for addition

Break numbers apart to add tens and ones separately.

Quick answer

Partitioning for addition means splitting numbers into tens and ones, then adding the tens together and the ones together to make addition easier.

Learning outcome

By the end of this page, you will be able to split numbers into tens and ones to add them more easily. Success signs:

You can break a number like 27 into 20 and 7
You can add tens and ones separately
You can use this method to solve addition problems
You can check your answer by adding the parts back together

Why this matters

Partitioning for addition helps you solve bigger addition problems without needing to use a calculator or count on your fingers. It's a useful strategy that makes maths easier, especially when you're adding numbers that are bigger than 10. This skill will help you in school, when you're working with larger numbers, and in everyday life when you're adding up money or counting things.

How it works

Partitioning for addition means splitting numbers into their tens and ones parts. Here's how to do it:

Look at the number you want to add
Split it into tens and ones
Add the tens together
Add the ones together
Add the two answers together

Let's try an example: 24 + 17 First, we split the numbers:

24 = 20 + 4
17 = 10 + 7

Next, we add the tens:

20 + 10 = 30

Then, we add the ones:

4 + 7 = 11

Finally, we add the two answers:

30 + 11 = 41

So, 24 + 17 = 41

Examples you can see

Let's look at more examples of how partitioning works. Example 1: 36 + 28

36 = 30 + 6
28 = 20 + 8
Tens: 30 + 20 = 50
Ones: 6 + 8 = 14
Total: 50 + 14 = 64

Example 2: 42 + 19

42 = 40 + 2
19 = 10 + 9
Tens: 40 + 10 = 50
Ones: 2 + 9 = 11
Total: 50 + 11 = 61

Example 3: 55 + 37

55 = 50 + 5
37 = 30 + 7
Tens: 50 + 30 = 80
Ones: 5 + 7 = 12
Total: 80 + 12 = 92

You can also use this method with larger numbers. Try this one: Example 4: 123 + 456

123 = 100 + 20 + 3
456 = 400 + 50 + 6
Tens: 100 + 400 = 500
Ones: 20 + 50 = 70
Units: 3 + 6 = 9
Total: 500 + 70 + 9 = 579

Try it as a mini adventure

Let's go on a treasure hunt! You are going to collect coins in a game. Here's your challenge: Adventure: The Coin Collection You are collecting coins for your treasure chest. You found these coins:

23 coins in a cave
18 coins in a tree
45 coins in a river

How many coins do you have altogether? First, let's split each number:

23 = 20 + 3
18 = 10 + 8
45 = 40 + 5

Next, add the tens:

20 + 10 + 40 = 70

Then, add the ones:

3 + 8 + 5 = 16

Finally, add the two answers:

70 + 16 = 86

You have 86 coins in your treasure chest! Let's try another one: Challenge: The Library Book Count You are helping to count books in the school library. You found:

67 books in the fiction section
34 books in the non-fiction section

How many books are there in total? Split the numbers:

67 = 60 + 7
34 = 30 + 4

Add the tens:

60 + 30 = 90

Add the ones:

7 + 4 = 11

Total:

90 + 11 = 101

There are 101 books in the library!

Common mistakes

Mistake: Forgetting to add the tens and ones together at the end.
Why it happens: Children may get excited about splitting numbers and forget to combine the results.
Fix: Always check your work by adding the tens and ones together at the end.
Mistake: Adding the tens and ones in the wrong order.
Why it happens: Some children may get confused about which numbers to add first.
Fix: Always split the numbers first, then add the tens together, then add the ones, then add the two totals together.
Mistake: Not splitting numbers correctly.
Why it happens: Children may confuse tens and ones, especially with numbers like 10 or 20.
Fix: Use visual aids like base-10 blocks or draw pictures to help understand the parts of numbers.

Parent and carer guide

As a parent or carer, you can help your child with partitioning for addition by:

Practising with everyday examples like counting money or adding up snacks
Using visual aids like base-10 blocks, drawings, or counters to show how numbers split
Encouraging your child to explain their thinking step by step
Checking that they add the tens and ones together at the end
Using games or activities that involve splitting numbers

Try these 5-minute activities:

Count objects together and split them into tens and ones
Use coins to practice splitting numbers
Play a game where you split numbers and add them
Draw arrays or groups to show partitioning
Ask your child to teach you how to do it

Remember, it's okay if your child makes mistakes. They're learning and growing! Celebrate their efforts and help them learn from errors.

Practice questions

Split 34 and 26, then add them together using partitioning.
Split 57 and 18, then add them together using partitioning.
Split 43 and 39, then add them together using partitioning.
Split 62 and 27, then add them together using partitioning.
Split 75 and 16, then add them together using partitioning.

Answers:

34 + 26 = 60 + 10 = 70
57 + 18 = 60 + 15 = 75
43 + 39 = 70 + 12 = 82
62 + 27 = 80 + 9 = 89
75 + 16 = 80 + 11 = 91

FAQ

What is partitioning in addition?

Partitioning in addition means splitting numbers into tens and ones to make adding easier.

Why do we use partitioning?

We use partitioning to make addition easier, especially with bigger numbers. It helps us break down the problem into smaller parts.

Can I use partitioning with any numbers?

Yes! You can use partitioning with any numbers, from small numbers like 12 + 15 to large numbers like 123 + 456.

How can I practice partitioning?

You can practice by splitting numbers into tens and ones, then adding them together. Try with coins, counters, or drawing pictures.

Is partitioning the same as regrouping?

Not exactly. Partitioning means splitting numbers apart, while regrouping means moving numbers between place values when adding or subtracting.