Adding decimals

Adding decimals works exactly the same way as column addition of whole numbers or integers.

When adding decimals it is important to keep the decimal points in line with each other.


Calculate \(3.6 + 14.73\).

Make sure that units line up with units, tenths line up with tenths and so on. Use zeros as placeholders if you need to.

Example of long addition
Remember all whole numbers have decimal places at the end of them, they are just not usually used.

David is doing some DIY. He buys a \({2}~m\) length of wood.

He needs to cut two pieces of wood - one of length \({0.6}~m\) and one of length \({1.02}~m\).

What is the total length of wood that David needs to cut?

Diagram of a saw and three pieces of wood

Add \(0.6\) and \(1.02\)

Adding decimals diagram: 0.6 + 1.02 = 1.62

So the total length of wood that David needs to cut is \({1.62}~m\).

You can add zeros to the end of a decimal without affecting its value, so 0.6 is the same as 0.60.