Multiplying with 2 MAFS.3.OA.3.7

Multiplying with 2 Write your doubles addition facts from 0 to10: 0+0= 1+1= 2+2= 3+3= 10+10=

Multiplying with 2 1 group of 5 1 x 5 = 5 Let’s double it!

Multiplying with 2 2 groups of 5

Multiplying with 2 2 groups of 5 What is the multiplication sentence for the model? What is the addition sentence for the model?

Multiplying with 2 2 groups of 5 What is the addition sentence for the model? 5 + 5 = 10 What is the multiplication sentence for the model? 2 x 5 = 10

When you multiply with 2, you are doubling your other factor. Multiplying with 2 When you multiply with 2, you are doubling your other factor. 2 x 4 is… 2 groups of 4… or, 4 doubled

When you multiply with 2, you are doubling your other factor. Multiplying with 2 When you multiply with 2, you are doubling your other factor. 2 x 4 is… 2 groups of 4… or, 4 doubled This is 1 group of 4.

When you multiply with 2, you are doubling your other factor. Multiplying with 2 When you multiply with 2, you are doubling your other factor. 2 x 4 is… 2 groups of 4… or, 4 doubled This is 1 group of 4. This is another group of 4.

Multiplying with 2 2 x 4 is… 2 groups of 4… When you multiply with 2, you are doubling your other factor. 2 x 4 is… 2 groups of 4… or, 4 doubled This is 1 group of 4. This is another group of 4. The 4 was doubled. Now there are 8 total stars. So, 2 groups of 4 is 8. 2 x 4 = 8

= 6 = 12 = 16 = 14 = 18 Multiplying with 2 2 groups of 3 (2 x 3) So, what is… 2 groups of 3 (2 x 3) 2 groups of 6 (2 x 6) 2 groups of 8 (2 x 8) 2 groups of 7 (2 x 7) 2 groups of 9 (2 x 9) = 6 = 12 = 16 Encourage students to model each problem, or use the doubling strategy they learned today. = 14 = 18

Multiplying with 2 Let’s look at our Multiplication Table…

Multiplying with 2 Find all the multiples of 2…

Multiplying with 2 What do you notice about all the multiples of 2? All multiples of 2 are even numbers. The order is skip counting by 2. The ones place always goes 0, 2, 4, 6, 8, then it repeats. The tens place is not always an even number.

Multiplying with 2 Let’s look at our 100 Chart…

Multiplying with 2 Look at the multiples of 2…

Multiplying with 2 What do you notice about all the multiples of 2 on this chart? You can see that the multiples of 2 are every other number. The columns help you to see the patterns in the ones place (0, 2, 4, 6, 8) and the tens place (goes up by 1 in each column).

Game: Rolling for Doubles 6 12 4 8 What each pair of students need: Rolling for Doubles Recording Sheet 1-6 Number Cube (regular dice) How to play: The taller player starts. Roll the dice and multiply that number by 2. Record the equation. Then the other player does this. After 3 rolls, sum the products. The player with the higher product wins that round. 1 2 6 12 3 6 5 10 20 30

What is one strategy you used for multiplying with 2? Closing What is one strategy you used for multiplying with 2? Skip count by two Double the other factor Draw it/model it Use a tool (100 chart, multiplication chart)

Bonus Question When you multiply any number by 2, can the product ever be an odd number? Why or why not? The product can never be odd, because when you are multiplying any number by 2, you double the number. Anytime you double a number that number has a pair. If there is a pair, then it is not odd, it is always even. Have students model multiplying numbers by 2 (e.g. with unifix cubes). When students multiply 2 by 3, they make 2 sets of 3 (so there is a pair of 3). When there is a pair of numbers, the total has to be even.

Exit Ticket Colin has 2 baskets with 4 bananas in each basket. How many bananas does Colin have? Model the problem. Write an equation that corresponds to it. Write another equation that corresponds to it. Write the answer to the problem in a complete sentence.