Odd and Even Numbers

In mathematics, numbers can be categorized as either odd or even. Understanding the difference between odd and even numbers is an important concept in early math education.

Even Numbers

An even number is a number that is divisible by 2, i.e., when you divide the number by 2, there is no remainder. Even numbers always end in 0, 2, 4, 6, or 8. The first few even numbers are 2, 4, 6, 8, 10, and so on.

Odd Numbers

An odd number is a number that is not divisible by 2, i.e., when you divide the number by 2, there is a remainder of 1. Odd numbers always end in 1, 3, 5, 7, or 9. The first few odd numbers are 1, 3, 5, 7, 9, and so on.

Identifying Odd and Even Numbers

To identify whether a number is odd or even, you can simply look at the last digit of the number. If it is even, the entire number is even. If it is odd, the entire number is odd.

Examples:

4 is an even number because the last digit is 4.
7 is an odd number because the last digit is 7.
12 is an even number because the last digit is 2.
15 is an odd number because the last digit is 5.

Understanding odd and even numbers is important for various mathematical operations and patterns. It also forms the foundation for learning about divisibility and other number properties.

◂Math Worksheets and Study Guides First Grade. Odd and Even

Identifying Even and Odd Numbers

The resources above cover the following skills:

Number and Operations (NCTM)

Understand numbers, ways of representing numbers, relationships among numbers, and number systems.

Count with understanding and recognize 'how many' in sets of objects.

Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.

Connect number words and numerals to the quantities they represent, using various physical models and representations.

Grade 1 Curriculum Focal Points (NCTM)

Number and Operations: Developing an understanding of whole number relationships, including grouping in tens and ones

Children compare and order whole numbers (at least to 100) to develop an understanding of and solve problems involving the relative sizes of these numbers. They think of whole numbers between 10 and 100 in terms of groups of tens and ones (especially recognizing the numbers 11 to 19 as 1 group of ten and particular numbers of ones). They understand the sequential order of the counting numbers and their relative magnitudes and represent numbers on a number line.

Connections to the Grade 1 Focal Points (NCTM)

Algebra: Through identifying, describing, and applying number patterns and properties in developing strategies for basic facts, children learn about other properties of numbers and operations, such as odd and even (e.g., 'Even numbers of objects can be paired, with none left over'), and 0 as the identity element for addition.