Even or odd: arithmetic rules

Learning Objectives Identify any whole number as even or odd based on its ones digit. Predict whether the sum of two numbers will be even or odd without calculating the exact sum. Predict whether the difference between two numbers will be even or odd without calculating the exact difference. Predict whether the product of two numbers will be even or odd without calculating the exact product. Apply the rules for adding, subtracting, and multiplying even and odd numbers to solve problems. Explain why the rules for even and odd numbers work using simple examples. If you have an even number of friends in a line and an odd number of friends join, will the new line be even or odd? 🤔 Let's find out! In this lesson, you will learn the secret rules for adding, subtracting, and...

TermDefinitionExample Even NumberA whole number that can be divided by 2 with no remainder. It always ends in a 0, 2, 4, 6, or 8.The number 34 is even because it ends in 4. Odd NumberA whole number that has a remainder of 1 when divided by 2. It always ends in a 1, 3, 5, 7, or 9.The number 129 is odd because it ends in 9. SumThe result you get when you add two or more numbers together.The sum of 7 and 5 is 12. DifferenceThe result you get when you subtract one number from another.The difference between 15 and 6 is 9. ProductThe result you get when you multiply two or more numbers together.The product of 4 and 3 is 12. PatternA set of numbers or objects that follow a specific, repeating rule.1, 3, 5, 7, 9 is a pattern of odd numbers.

Addition & Subtraction Rules Even ± Even = Even Odd ± Odd = Even Even ± Odd = Odd Use these rules to quickly find out if an answer will be even or odd. Notice that when the numbers are the same type (both even or both odd), the result is Even. When they are different, the result is Odd. Multiplication Rules Even × Any Number = Even Odd × Odd = Odd Use these rules to predict the outcome of multiplication. The most important rule is that if you multiply any number by an even number, the product is always Even. The only way to get an odd product is by multiplying two odd numbers.