Relate Area to Multiplication
10 min
Narrative
This Warm-up prompts students to compare four images. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology to describe the characteristics of area.
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 are completely shaded.
A, B, and D go together because:
- They are rectangles.
A, C, and D go together because:
- They are wider than they are tall.
- They have labels on the side lengths.
B, C, and D go together because:
- They have grid lines.
Synthesis
- “Why do all 4 go together?” (They have shaded parts. The labels or cubes that we can count show us their side lengths. For each image, 6 represents the value of the shaded part.)
Standards
Building Toward
- 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.