What is an integer?

An integer is simply a whole number. This can be a negative or positive number; 0 is also classified as an integer.

When children start to learn about decimals (usually in Year 4), they will be taught that a decimal such as 0.3, 0.82, 0.1 etc, is not a whole number, it is a part of one whole. Numbers such as 8.3, 1.9, 2.63 are made up of whole numbers and decimals, so cannot be classified as integers.

Here is an example of a puzzle involving the term 'integer' that may be given to a more able Year 6 child:

Which integer do you multiply 0.9 by to make 5.4?

Here, a child could use their knowledge of the 9 times table to work out that 9 x 6 = 54, so 0.9 x 6 must equal 5.4.

Another good puzzle for a more able Year 6 child is:

How many ways can you make 1000, as the sum of consecutive integers?

Part of the purpose of giving children investigations like these is to test their ability to tackle a puzzle. However, another important reason for giving puzzles like this to children, is that it tests their knowledge of mathematical vocabulary. This puzzle requires them to know the words: sum, consecutive and integer.