Page 165 - NUMINO TG_5A

Activity 2 Multiplying Mixed Numbers

jOb ective Multiply mixed numbers using new methods.

1. Textbook Instructions Activity 2 Multiplying Mixed Numbers

Learn how to multiply mixed numbers.

Students will use a model method to begin to

multiply two mixed numbers together. Solve Method 1 Use models.

the first problem for students. 1 1
2 3
Example: 2 1 2 1 Multiply 2 2
2 3
3
Step 1: Shade 2 1 of the rows in the Shade 2 1 of the columns.
2 3 21
2
model. Shade 2 1 of the rows. 2
2
1
Step 2: Shade 2 3 of the columns in the

Find the area of the colored part. 1
0
model. 1 1 = 1 1
2 3 6 _21
Step 3: Find the area of a single shaded

square. 0 _31 1 1 2 21 3
3
111

236 Count the number of colored parts.
5 7 = 35
Step 4: Count the number of parts shaded by

both colors. 35 parts. Multiply to find the product.

Step 5: Multiply the number of parts by the 35 1 = 35 = 5 5
6 6 6
area of one part to find the product.

35 1 35 1 . Multiply mixed numbers using the method above.
6 6

Step 6: Simplify a. 2 b. 2

35 5 5 1 1 1 1
6 6 2 3

1 1

1. Have students solve the problems using 0 1 1 1 2 0 1 2 3 3 1 4
the method above. 2 2
1 1 1
1 1 1 2 = 9 1 1 1 3 2 = 28 6
2 4 3

91 = 218 =4 2
6
92 = 4 = 2 4 3

2. Build Understanding

Students may have difficulty when using the model method. A common error is miscalculating the area of

one segment of the model.

Example: Rows are broken into 1 segment, columns into 1 segment, but the student accidentally
2 3

calculates assuming two 1 segments.
2

111

224

This will result in an incorrect final product. Encourage students to be sure of their measurements before

they make final calculations.

148 NUMINO Teacher s Guide