Page 143 - NUMINO TG_4A

Activity 1 Multiply 3-Digit Numbers by 2-Digit Numbers

jOb ective Multiply a 3-digit number by a 2-digit number.

1. Textbook Instructions Activity 1 Multiply 3-Digit Numbers by 2-Digit Numbers

Students will learn how to multiply a 3-digit 1 . There are 20 cookies in a box.
number by a 2-digit number.
How many cookies are there in 375 boxes?

1. Show the students how to multiply a 3-digit
number by a multiple of ten.

Method 1: Use a pattern to find the product.

Refer to .

Method 2: Show students how the product
can be found using the vertical form.

Multiply 375 by 0 ones. Find the pattern and fill in the blanks.
375 0 ones 000 Then learn how to multiply 375 by 20.
Multiply 375 by 2 tens.
375 20 7,500 and 375 2= 750
Find the sum of the products in step 375 20 = 7,500
step .
375 20 7,500 375 375 375 3 75
20 20 20 20
0 0 0

7500 7 5 00
7, 5 0 0

76

2. Build Understanding

Have the students find a pattern in how these numbers are multiplied to find the product.
Example: 500 700

Four 0’s 0,000

500\700 = 35

5\7 = 35

126 NUMINO Teacher s Guide