Level 3-4 Numbers - Decimals - Adding and Subtracting

Adding and subtracting - what could be simpler? But decimal numbers can cause problems for the unwary! In this KS3 Maths quiz we'll help you get to grips with adding and subtracting decimals.

Decimal numbers contain decimal points, on the left of which are ones and on the right tenths, hundredths and thousandths. We use decimal numbers as an alternative to fractions to describe numbers that are smaller than a one. For example, the fraction ¹⁄₈ could also be written as 0.125. Here we have 1 tenth, 2 hundredths and 5 thousandths. Decimal numbers make addition, subtraction, multiplication and division of fractions much easier. It's just like normal addition and subtraction, except you have to remember to line up the decimal point and add zeros where necessary.

Play this quiz to help familiarise you with adding and subtracting decimal numbers. Plenty of practise and it'll soon become second nature to you.