Introduction
When we are asked to add numbers such as 15 + 5, we can often work out the answer mentally
( in our heads).
However, when we are given questions with bigger numbers, we usually need to use a written method.
In this activity, we will look at the columnar method to add numbers.
Let’s have a look at how we can use the method to add 342 + 442
First, we write the numbers in columns under the correct unit (hundreds, tens, ones).
H T O
3 4 2
4 4 4
Starting at the right-hand column (ones), we add each column and write the answers underneath.
H T O
3 4 2
4 4 2
7 8 4
342 + 442 = 784
Here is another example:
H T O
6 7 2
3 2 5
9 9 7
672 + 325 = 997
With this method, it is important that we start with the ones column. This is because when the digits in a column add up to ten or more, we have to exchange (sometimes known as ‘carrying’ numbers). We will look at this in another activity!
Now, why don’t you have a go at answering some questions using this method?
