Odd and Even Numbers Definition

Odd numbers cannot be partitioned into two equal integers. For example, three can be partitioned into a group of one and a group of two. As these groups are not equal, three is an odd number. Odd numbers are not divisible by two.

Even numbers can be partitioned into two equal integers. For example, four can be partitioned into two groups of two. As these are equal groups of whole numbers, four is an even number. Even numbers are divisible by two, with no remainders.

Examples of Odd and Even Numbers

Odd numbers have a ones digit of 1, 3, 5, 7 or 9. For example, 21 and 4751 are both odd numbers because they both have 1 in the ones position.

Even numbers have a ones digit of 0, 2, 4, 6 or 8. For example, 74 and 2914 are both even numbers because they both have 4 in the ones position. Even numbers are always multiples of two because they can be partitioned into two equal groups of whole numbers.

What Does the National Curriculum in England Say?

Year 1: Number – Number and Place Value

Non-Statutory Guidance:

• They practise counting as reciting numbers and counting as enumerating objects, and counting in twos, fives and tens from different multiples to develop their recognition of patterns in the number system (for example, odd and even numbers), including varied and frequent practice through increasingly complex questions.

Year 2: Number – Multiplication and Division

Pupils should be taught to:

• recall and use multiplication and division facts for the 2, 5 and 10 multiplication tables, including recognising odd and even numbers.

Explaining Odd and Even Numbers in the Classroom

Children initially start to explore odd and even numbers within ten. The non-statutory guidance suggests activities that develop children’s recognition of patterns in the number system. Children can start by sorting objects into two groups to identify odd and even numbers and then progress to visual representations of odd and even numbers. For example, placing counters or images onto a ten-frame in a systematic way can help children identify and understand whether a number is odd or even. In the example below, you can see images of people placed on a ten-frame.

Children can learn to identify odd and even numbers using a number line. They will notice the pattern that alternate numbers are odd and even.

They can also learn to use a 100 square to identify odd and even numbers.

Children will learn that numbers with a ones digit of 0, 2, 4, 6, 8 will always be an even number, whereas numbers with a ones digit of 1, 3, 5, 7, 9 will always be an odd number. Using this knowledge, children will learn to identify larger odd and even numbers and sort them accordingly.

Odd and Even Number Resources

• KS1 Maths - Odd and Even Numbers Powerpoint
• Ten-Frame Buses Odd and Even Numbers PowerPoint
• Year 1 Number: Odd and Even Numbers Lesson
• Odd and Even Numbers Ladybirds Colouring Worksheet
• Caterpillars Odd and Even Numbers Worksheet - Twinkl
• Odd and Even Numbers Challenge Cards
• Ten-Frame Buses Odd and Even Numbers Activity Sheet
• Year 1 Odd and Even Numbers Maths Game
• Odd and Even Numbers Resource Game Pack
• PlanIt Maths Year 2 Multiplication and Division Lesson Pack 11: Odd and Even Numbers

Teaching Video About Odd and Even Numbers