Many of the techniques used for addition and subtraction within 20 will be the same as those the children learned for Addition within 10 and Subtraction within 10 - such as "counting on" - and other previous sections. Children should by now be very familiar with adding numbers up to 10 and number bonds up to 10. However, one of the most important skills for mental maths and for much of what comes later will also be learned here - that of adding by grouping or "making 10". We've provided plenty of ways to practise and ideas for making it interesting below. Or scroll down to find our printable resources.

We look at 3 different techniques for adding within 20 here:

## Making It Real

• Kitchen fun. Anything edible makes maths fun! Grab a packet of cookies, a container of small sweets or similar and start by placing 8 in front of your child. Count them. Now put 3 more down on the table. Count again. So 8 + 3 makes 11. Try the same thing but this time start with 9 (count) and add a larger number like 7 or 8 (count again). Discuss with your child how slow this counting process can be!

## 1. Adding By Counting On

Counting on is a useful skill when adding a small number (1, 2, 3 or maybe 4) to a larger number. Many children struggle with counting on, however, because they start by counting the big number rather than counting on to the next. It can be useful, therefore, to start by physically keeping the big number to one side and the smaller number to the other side, as in the ideas below. Once your child becomes familiar with the technique, the separation will no longer be necessary.

• Finger hopping. Put 8 items (manipulatives, sweets etc) on the table, slightly to the left of your child. Now line up 3 of the same items, slightly to the right of your child. Point to the group of 8 and count them. Now, make exaggerated hops with your finger as you count on.

• Which is easier? Is it easier to add 9 + 2 or 2 + 9 using counting on? Try this by finger hopping with a number line. Start with a finger on 9 and then hop along counting 1, 2 to get to the answer. Now start on 2 and hop along counting 1, 2, 3, 4, 5, 6, 7, 8, 9. Try this with 3 + 8 and 8 + 3 and other combinations of numbers.
• Worksheets. You will find our "Addition by Counting On" and "Addition to 20 Using Number Lines" worksheets in the Resources section below.

## 2. Adding By Making 10

Counting on and number lines are a good way to get children started on adding bigger numbers, but both have their limitations. Counting on gets tricky when you are adding bigger numbers together, and number lines aren't always available or practical! One strategy to help children add 2 numbers, when the first number is less than 10, is to redistribute the number to "make 10" and then add 10 to the remainder. Adding by making 10 is a really useful skill for much that comes later as well as having many real life uses, so the more practice the children get at this stage, the better.

• Revise. Children who have easy and instant recall of Number Bonds to 10 will have an advantage here, so you might want to revise these by playing Snap Challenge, or going back to look at more ideas for learning these essential maths facts. Also, all the work you did on Counting on from 10 and "looping" skills comes into its own now! You might want to go back and print out some of our worksheets for some quick revision.
• 10+. Children should by now be able to quickly answer any addition sum up to 20 that starts with a 10 - for example, 10 + 5 = 15 or 10 + 7 = 17. If not, now is the time to practice. We have 2 simple worksheets below for extra help.
• Ten frames. Gather 2 Ten Frames - or better still, our Numbers to 20 Frames or Numbers to 20 Towers - and a stack of counters. Put 8 or 9 counters on one frame, and 3 or 4 counters on the other. Now experiment with your child to find different ways of counting the combined counters. You could start by counting on. Now try moving counters from the second frame onto the first to fill it up, or "make 10". Now count the extras and add to 10. Much quicker! Some children will realise that they are using their knowledge of Number Bonds to 10 and will grasp this concept quickly while others will need plenty of hands-on practice, moving counters from one frame to another and re-counting the counters each time.
• Worksheets. You can use our set of Add by Making 10 worksheets to practice this skill, together with a printable of the illustration below, in the Resources section.

We have a printable of this illustration available below.

Watch this method and our worksheets in action as Shelly teachers her son how to add by "making 10".

If one of the 2 numbers to be added is greater than 10, children can make use this third method. This process builds on our Loop 10 and Count Worksheets set 1, so you might want to go back to these for revision first.  It's a very useful skill to practice for mental maths agility later, and also introduces the concept of "tens" and "units" - without specifying them as such - to the children for the first time. The larger number is split into one "ten" and a number units. The units are added together, and that total is added to 10. So, for example:

13 + 5 becomes 10 + 3 + 5 or 10 + 8, or 18.

Use manipulatives to practice this until your child is confident. We also have a printable version of this diagram, and two sets of worksheets using this addition method below.

## Our Addition Within 20 Resources

All the resources mentioned above, together with other printables you may find useful when learning addition and subtraction within 20, can be explored by clicking the links below. They are in alphabetical rather than suggested-use order.

## 10 Plus Facts Worksheets

We have two simple worksheets to help your child learn - or revise- their addition facts from 10 + 0 to 10 + 20. If you can work on instant recall for these, adding by "making 10" becomes much easier.

## Add By Making 10 Worksheets Set 1

One strategy to help children add 2 numbers, when the first number is less than 10, is to redistribute the number to "make 10" and then add 10 to the remainder.

Use this poster when explaining how to add by adding units, or have it on hand on your child's desk as a reminder when they try this method of addition for the first time.

Here are 20 addition problems over 2 worksheets aimed at helping children practice addition using the "adding by adding units" technique - ie breaking down the bigger number into 10 and units.

## Addition and Subtraction Story Sums Within 20

Here's a mixed set of story sums to help children practise addition and subtraction within 20 - and put the use of maths into an everyday context.

## Addition by Counting On Worksheets Set 5

This set of 4 worksheets helps children practice addition by counting on - counting on 1, 2 or 3 to get double digit figures up to 20. Each worksheet builds on the previous one.

## Addition to 20 Using Number Lines

Using number lines to allow children to "hop" along the line is another way to practice addition by counting on. These 2 worksheets include a simple number line for the children to use as they solve the addition problems given.

## Addition Within 20 Practice Worksheets Set 1

With 30 simple addition within 20 problems per worksheet and 2 worksheets in this pack, there is plenty of practice for the kids here. We've added a extra challenge at the end too.

Here is a blank template for you to create your own arithmagons using addition facts - perfect for when your child is struggling with a particular number bond or needs more practice than we have already provided.

## Arithmagons Pack 2

This pack of 16 arithmagons (over 4 pages) helps children learn their addition and subtraction facts up to 20 - in puzzle format. It's a great way to learning maths into a fun challenge for the kids.

## Bee Hive Adding and Subtracting Within 20

Help the bees solve the addition and subtraction problems on these fun worksheets. There are 2 sets of problems in the pack to provide plenty of practice, all within 20.

Here's a fun way to practise addition of two numbers up to 12, using 2 normal dice and our game board with colouring pencils or counters. You can try this as a single player game against the clock, or as a multi player game.

## Christmas Stockings Addition Peg Cards

Here's a fun way to practise simple addition skills with a Christmas stocking theme! Print and cut out the peg cards, the ask the children to do the sum and peg the answer. There are 5 pages with 20 cards in total, and you can choose between colour or black and white.

## Count on from 10 Worksheets Set 3

Our third set of "count on from 10" worksheets sticks with the 10 frame + more format, but this time asks children to fill in the missing numbers of an addition sum underneath the illustration.

Count the flowers and write the sums beneath. There are six questions on this worksheet, with addition up to 20.

Practising addition is fun with our fishy dice game! Roll two dice, add up the numbers and colour in the fish with the correct answer - you can time yourself against the clock, or play against a friend!

Here's a fun way to practice addition, with the help of some pretty flowers! Roll two dice, add up the numbers and colour in the answer - you can time yourself against the clock, or play against a friend!

This game is played between two players, who compete to colour in the most footballs!

## Halloween Adding to 20 Peg Cards

Here's a fun way to practise adding to 20 with a spooky Halloween twist. Print and cut out these Halloween Addition peg cards, then ask the kids to try the sums and "clip" the correct number at the bottom of each card.

There are 4 worksheets in this set, providing practice for another addition skill for children - this timeĀ  splitting the larger of 2 numbers into 10 and the remainder, then adding the remainder to the smaller number. It's a useful tactic to have under your belt!

## Make 10 Illustration Printable

Just in case our illustration on how to practice "making 10" with number lines is useful, we provide a printable version here. You can find similar Make 10 Worksheets here.

## Match the Carriage with the Engine up to 20

Here's a fun way to practise adding up to 20. The children need to work out the sum on the train carriage and match it to the correct engine. There are 5 pages in this set.

## Number Line Banner 0-20

Choose from colour or black and white for this long banner featuring the numbers from 0-20. We've designed it so that it is quick to print and assemble and it looks great on the classroom walls...

## Number Lines to 20 - Bordered - Numbers Above

Here are some colourful, bordered number lines to 20 to print for children learning to count, count on, add and subtract.

## Number Lines to 20 - Bordered - Numbers Below

Print this colourful bordered number lines to 20 in 5 different colours - or just choose the colour that you prefer and print that page as many times as required. Each page gives you 3 bordered number lines from 0 to 20.

## Number Lines to 20 - Kids

These fun printable number lines to 20 have a parade of children ready to encourage the kids in their counting! They print 2 to a page and are simply sliced apart.

## Number Lines to 20 - Kids - Dotty

Kids will love learning to count to 20 with these fun printable number lines! There are two on the page, ready to be sliced apart.

## Numbers to 20 Frames

Print out these frames, laminate them if you wish, and use them with counters or other small objects for learning to count on from 10, addition within 20, subtraction within 20 etc.

## Numbers to 20 Towers

Each of this printable provides two useful double-sets of ten towers, perfect for learning to count on from 10 to 20, addition within 20 and so on. They come in a variety of colours and we've included 3 sets of 20 counters too.

Practise addition skills with the help of some cute pigs! Roll two dice, add up the numbers and colour in the answer - you can time yourself against the clock, or play against a friend!

Help practise addition skills with a seaside theme! Roll two dice, add up the numbers and colour in the answer on the correct bucket and spade - you can time yourself against the clock, or play against a friend!

Here's a fun way to practice addition, with the help of some suns! Roll two dice, add up the numbers and colour in the answer - you can time yourself against the clock, or play against a friend!