Multiply Fractions
10 min
Narrative
This Warm-up prompts students to compare four different shaded regions in order to introduce the new type of region that will be considered in this lesson, namely regions where neither side length is a unit fraction. It gives students a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminologies students know and how they talk about regions with fractional side lengths. During the discussion, focus on Diagram A, which has a rectangular region where both sides are non-unit fractions.
Launch
- Groups of 2
- Display the image.
- “Pick 3 that go together. Be ready to share why they go together.”
- 1 minute: quiet think time
Teacher Instructions
- “Discuss your thinking with your partner.”
- 2–3 minutes: partner discussion
- Share and record responses.
Student Task
Which 3 go together?
Sample Response
Sample responses:
A, B, and C go together because:
- They show a single unit square.
A, B, and D go together because:
- For each of them, there are 12 pieces in the whole square.
A, C, and D go together because:
- They have 6 shaded pieces.
B, C, and D go together because:
- They have a shaded region that has a unit fraction for a side length.
Activity Synthesis (Teacher Notes)
- Display Diagram A.
- “What is the area of the shaded region? How do you know?” (126 because there are 6 shaded pieces and there are 12 pieces in the whole square.)
Standards
- 5.NF.4.b·Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.
- 5.NF.B.4.b·Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.
15 min
20 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Multiply Fractions
10 min
Narrative
This Warm-up prompts students to compare four different shaded regions in order to introduce the new type of region that will be considered in this lesson, namely regions where neither side length is a unit fraction. It gives students a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminologies students know and how they talk about regions with fractional side lengths. During the discussion, focus on Diagram A, which has a rectangular region where both sides are non-unit fractions.
Launch
- Groups of 2
- Display the image.
- “Pick 3 that go together. Be ready to share why they go together.”
- 1 minute: quiet think time
Teacher Instructions
- “Discuss your thinking with your partner.”
- 2–3 minutes: partner discussion
- Share and record responses.
Student Task
Which 3 go together?
Sample Response
Sample responses:
A, B, and C go together because:
- They show a single unit square.
A, B, and D go together because:
- For each of them, there are 12 pieces in the whole square.
A, C, and D go together because:
- They have 6 shaded pieces.
B, C, and D go together because:
- They have a shaded region that has a unit fraction for a side length.
Activity Synthesis (Teacher Notes)
- Display Diagram A.
- “What is the area of the shaded region? How do you know?” (126 because there are 6 shaded pieces and there are 12 pieces in the whole square.)
Standards
- 5.NF.4.b·Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.
- 5.NF.B.4.b·Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.