Lesson 2: What Is Multiplication?
Activities
Activity 1: Why Do We Multiply?
Give your child time to watch the read aloud of Amanda Bean's Amazing Dream (written by Cindy Neuschwander) at the following web link. This book explains why multiplying is often better and easier than counting.
Web Link
Once your child has watched the video once, allow her to look back through the images in it as you ask her the following questions:
- Why does Amanda Bean's teacher want her to learn how to multiply? (because it's faster than counting)
- What are some things that Amanda Bean wants to count? (possible answers: tiles on the countertop, books on the bookcase, wheels on the bicycles, legs on the sheep, balls of yarn held by the sheep, the grandmas' knitting needles, arms on the sweaters)
- What are some examples of arrays in the book? (possible answers: window panes, lollipops, cookies, cakes, brownies, tiles)
- Where do you see equal groups? (possible answers: lollipops, flowers on cakes, food in jars, books on shelves, wheels on bikes, balls of yarn, knitting needles)
- Just like there is a symbol for addition and one for subtraction, there's also a symbol for multiplication. What is it? (×)
Tell your child that she will work with Amanda Bean's Amazing Dream again in upcoming lessons.
Activity 2: What is Multiplication?
Materials: counters (kit), fine point dry-erase markers (kit), whiteboard (kit)
Say, "Multiplication is a mathematical operation that helps us count groups of things, and when you know your multiplication facts like you know your addition facts, you can count things really quickly."
Show 4 groups that each have 5 counters, and say, "I could count these one at a time, but if I understand multiplication, I can figure out how many counters there are in all much more quickly." Write 4×5= on the whiteboard. Point to the 4 and the 5, and say, "We call these factors. Factors are the numbers that we multiply together to find a product, or an answer to a multiplication problem. The × between the factors tells me to multiply them. In this example, I have 4 groups of counters, and there are 5 counters in each group. Because I know how to count by 5, I can use this approach to figure out the product." Model counting by 5 to get to a total of 20, and say, "Four times five equals 20." Write 20 at the end of the multiplication sentence: 4×5=20.
Now, show 2 groups that each have 3 counters. Say, "This shows 2 groups of 3 counters or two times three." Ask your child to write "two times three" on the whiteboard using numbers and the multiplication symbol. She should write "2×3."
Show 4 groups that each have 5 counters, and say, "I could count these one at a time, but if I understand multiplication, I can figure out how many counters there are in all much more quickly." Write 4×5= on the whiteboard. Point to the 4 and the 5, and say, "We call these factors. Factors are the numbers that we multiply together to find a product, or an answer to a multiplication problem. The × between the factors tells me to multiply them. In this example, I have 4 groups of counters, and there are 5 counters in each group. Because I know how to count by 5, I can use this approach to figure out the product." Model counting by 5 to get to a total of 20, and say, "Four times five equals 20." Write 20 at the end of the multiplication sentence: 4×5=20.
Now, show 2 groups that each have 3 counters. Say, "This shows 2 groups of 3 counters or two times three." Ask your child to write "two times three" on the whiteboard using numbers and the multiplication symbol. She should write "2×3."
Give your child time to watch the video at the following web link. This video reinforces that multiplication is about counting groups of things and shows how to write multiplication sentences.
Web Link
Your child will complete the "Creating Multiplication Sentences" sheet using the example provided on it.
"Creating Multiplication Sentences" Answer Key
Student Activity Page
Student Activity Page