Multiplying by 2 and 4: Key Concepts and Techniques

What is the sum of two groups of eight?

• 20

• 18

• 16

• 14

How many groups of five are there in the sum of 20?

• 5

• 4

• 3

• 2

What does 2 * 8 represent?

• Eight groups of two

• Two groups of eight

• Sixteen groups of one

• One group of sixteen

How many costumes do two students with three costumes each have in total?

• 3

• 9

• 5

• 6

What does the number 2 represent in the multiplication 2 * 3?

• Number of students

• Number of groups

• Number of costumes

• Number of dots

What is the product of 2 * 5?

• 10

• 11

• 8

• 9

What pattern do you notice in the products of multiples of 2?

• They are all prime numbers

• They are all even numbers

• They are all multiples of 3

• They are all odd numbers

How many costumes do four students with two costumes each have in total?

• 6

• 9

• 7

• 8

What is the first step in using the doubling strategy to find 4 * 5?

• Subtract 2

• Multiply by 4

• Multiply by 2

• Add 5

What is the final product of 4 * 5 using the doubling strategy?

• 10

• 15

• 25

• 20