Decimals are numbers that lie between two whole numbers. For example, between 1 and 2, all the numbers starting from 1.1 up till 1.9 are decimal numbers. The decimal point (.) separates the ones place from the tenths place. Just like whole numbers, decimals can be added, subtracted, multiplied and divided. Decimals provide a precision of any amount, for example the cost of an item of \$3.67.

Decimals are simple to look at when laid in this context:

Think of one whole unit number. Say it’s the number 1. If you are splitting number 1 in 10 parts, every part has a value of one tenth. So if a number read 1.58, the number 5 means it is worth 5 tenths. The next number from 5 is 8. This number is the value in hundredths.

Similarly, \$3.67 means 3 is a whole amount. The 60 cents are 6 lots of dimes as a dime is one tenth of a dollar. The 7 cents will be made of four lots of cents as 1 cent is one hundredth of a pound.

When working with decimals in mathematics, you don’t need to worry much at the beginner’s level. Decimals are added and subtracted in the same way as whole number are. So 3.67 + 1.5 will be added normally, to get 5.17. And the subtraction can be done the same way: 3.67 – 1.5 will give 2.17. 