How to add and subtract, teaching kids maths at home, KS1/KS2

Maths - Addition and Subtraction Written Methods

The way addition and take away is taught in schools is different to how many people may remember being taught when they were at school.

Early Years / Key Stage 1

Children will begin to add and subtract in Early Years (Foundation 2) and key stage 1. At this stage they will be using lots of practical methods of counting e.g. using cubes, beads, counters, almost anything you can think of! They begin by understanding that 'add' means to combine two groups of objects and subtract means 'taking away' objects. Children will begin by using numbers up to 5, then numbers to 10, then numbers to 15 or 20 depending on their ability.

Children then move onto counting on and counting back. This can be done using number lines, where they start at a number and count on by making jumps along the number line in 1's.

Key Stage 2

As children move into key stage 2, they are introduced to different ways of adding and taking away. By Year 5, most children will be able to use more efficient, written down methods for addition and subtraction. Children will begin to use increasingly larger numbers ( numbers over 10,000), as well as using decimal numbers and roman numerals.

The methods used by schools varies.

Partitioning Method

This is where the numbers being added or subtracted are partitioned in hundreds, tens and units. The partitioned numbers can then be added or subtracted.

e.g. 123 + 76 = 278 - 23 =
123 + 70 = 193 278 - 20 = 258
193 + 6 = 199 258 - 3 = 255

Other Methods of Adding or Subtracting

Other written methods taught to children at school can include the expanded column method and the short column methods (as taught traditionally e.g. by carrying numbers). Children will also continue using numbers lines, but in Key Stage 2 they will be expected to draw their own number lines.

In many schools, teachers want to make sure children can add and subtract mentally, and using written methods. This is part of the reason why the more formal, quicker, written methods (the one most of us are familiar with) isn't taught until Years 4 or 5 (KS2). They want the children to understand the value of numbers and what happens to these numbers when you add and subtract, before showing the quicker methods of carrying (addition) and decomposition (subtracting). The use of number lines first, helps children's confidence adding and subtracting mentally.

Throughout Key stage 2, children will be using the skills they have learnt for adding and subtracting to solve word problems. This can involve 1 and 2 step problems, where children may need to do a few sums before reaching the final answer.

Join Teach My Kids and gain access to Maths worksheets that work through the methods taught at school using clearly explained with examples.