Unit 3, Lesson 9
Apply Fraction Multiplication
Grade 5
Activity 1
Jada has a small replica of the flag of Thailand.
It is 5 inches wide and inches long.
- What is the area of the flag? Explain or show your reasoning.
- Each red stripe is inches wide. What is the area of each red stripe? Explain or show your reasoning.
- The blue stripe is inches wide. What is the area of the blue stripe? Explain or show your reasoning.
Activity 2
Rectangle. Partitioned horizontally into 3 rows. Top colored yellow, middle, blue, bottom, red. Yellow row about half width. Other rows, each about 1 fourth width.
Han has a replica of the flag of Colombia.
It is inches wide and inches long. The yellow stripe is of the width of the flag. The blue and red stripes are each of the width.
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. The answer is inch. What is the question?
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and . The answer is square inches. What is the question?
Student Section Summary
We learned how to multiply different kinds of fractions.
First, we learned how to multiply a unit fraction by a unit fraction.
Example:
Diagram A shows of of a square is the same size as of the whole square. So, .
Next, we learned how to multiply a unit fraction by a non-unit fraction.
Example:
Diagram B shows of of a square is the same size as of the whole square. So, .
Finally, we learned how to multiply a non-unit fraction by a non-unit fraction.
Example:
Diagram C shows or 20 pieces shaded with or 42 pieces in the whole square.
We can use multiplication to represent the relationship.
- Find the numerator,
- Find the denominator,
- Represent the relationship with an equation: