Multiply by 8

Learning Objectives Recite the multiplication facts for 8 from 0 to 10. Use the 'double-double-double' strategy to solve any multiplication problem with 8. Solve one-step word problems involving multiplication by 8. Represent multiplication by 8 using arrays and repeated addition. Identify patterns in the products of the 8s times table. Apply the commutative property to solve 8s facts (e.g., know that 8 x 5 is the same as 5 x 8). Did you know an octopus has 8 arms and a spider has 8 legs? 🐙 How many arms would 3 octopuses have all together? In this lesson, we will become experts at multiplying by the number 8! Learning your 8s facts will help you solve math problems much faster and see how numbers can be broken down in cool ways. It's a key skill for becomin...

TermDefinitionExample MultiplicationA fast way to do repeated addition of the same number.Instead of writing 8 + 8 + 8, we can write 3 x 8. FactorThe numbers that are multiplied together in a multiplication problem.In 8 x 4 = 32, the numbers 8 and 4 are the factors. ProductThe answer to a multiplication problem.In 8 x 4 = 32, the number 32 is the product. Repeated AdditionAdding the same number over and over again.8 x 5 is the same as 8 + 8 + 8 + 8 + 8. ArrayAn arrangement of objects in equal rows and columns to show multiplication.An array for 2 x 8 would have 2 rows with 8 items in each row. Commutative PropertyThe rule that says you can swap the order of the factors and still get the same product.8 x 6 is the same as 6 x 8. Both equal 48.

The Double-Double-Double Strategy 8 \times n = (n \times 2) \times 2 \times 2 To multiply a number by 8, you can just double it three times. This works because 2 x 2 x 2 = 8. Using the 4s Facts 8 \times n = (4 \times n) \times 2 If you already know your 4s times tables, you can find the answer for an 8s fact by doubling it. This is because 8 is double 4.