Lesson 8 Apply Fraction Multiplication

- Let’s solve problems about flags.

Warm-up Number Talk: Fraction Multiplication

Find the value of each expression mentally.

$\frac{1}{3} \times \frac{3}{5}$
$\frac{2}{3} \times \frac{3}{5}$
$\frac{5}{3} \times \frac{3}{5}$
$\frac{2}{3} \times \frac{13}{5}$

Activity 1 Flags

Image of flag. Five rows. Colors from top to bottom are: red, white, blue, white, red. Blue row is wider than other rows.

Jada has a small replica of a flag of Thailand.

It is 5 inches wide and $7 \frac{1}{2}$ inches long.

What is the area of the flag? Explain or show your reasoning.
Each red stripe is $\frac{5}{6}$ inches wide. What is the area of each red stripe? Explain or show your reasoning.
The blue stripe is $\frac{10}{6}$ inches wide. What is the area of the blue stripe? Explain or show your reasoning.

Activity 2 More Flags

Rectangle. Partitioned horizontally into 3 rows.

Han has a replica of the flag of Colombia.

It is $3 \frac{1}{2}$ inches wide and $5 \frac{1}{4}$ inches long. The yellow stripe is $\frac{1}{2}$ of the width of the flag and the blue and red stripes are each $\frac{1}{4}$ of the width.

$\frac{1}{4} \times 3 \frac{1}{2} = \frac{7}{8}$ . The answer is $\frac{7}{8}$ inch. What is the question?
$\frac{1}{2} \times 3 \frac{1}{2} = \frac{7}{4}$ y $\frac{7}{4} \times \frac{21}{4} = \frac{147}{16}$ . The answer is $\frac{147}{16}$ square inches. What is the question?

Practice Problem

Problem 1

This flag of Sweden is $3 \frac{1}{5}$ inches wide and 2 inches tall. The rectangle in the upper right is $\frac{9}{5}$ inches wide and $\frac{4}{5}$ inch tall.

What is the area of the whole flag?
What is the area of the rectangle in the upper right?