Fractional Side Lengths Less than 1
10 min
Narrative
The purpose of this Estimation Exploration is for students to practice the skill of estimating a reasonable answer based on experience and known information. It gives students a low-stakes opportunity to estimate the area of a rectangle when one side is not a unit fraction.
Launch
- Groups of 2
- Display the image.
- “What might be the area of the shaded region?”
Teacher Instructions
- 1 minute: quiet think time
- 1 minute: partner discussion
- Record responses.
Student Task
What is the area of the shaded region?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 2 to 3
- About right: 4 to 6
- Too high: 621 to 7
Activity Synthesis (Teacher Notes)
- “Is more than half or less than half of the rectangle shaded?” (More than half)
- “How can you use this to help make your estimate?” (Half of 7 is 321 so it’s a little more than that.)
- “Based on this discussion does anyone want to revise their estimate?”
Standards
Addressing
- 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.
20 min
15 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Fractional Side Lengths Less than 1
10 min
Narrative
The purpose of this Estimation Exploration is for students to practice the skill of estimating a reasonable answer based on experience and known information. It gives students a low-stakes opportunity to estimate the area of a rectangle when one side is not a unit fraction.
Launch
- Groups of 2
- Display the image.
- “What might be the area of the shaded region?”
Teacher Instructions
- 1 minute: quiet think time
- 1 minute: partner discussion
- Record responses.
Student Task
What is the area of the shaded region?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
Sample responses:
- Too low: 2 to 3
- About right: 4 to 6
- Too high: 621 to 7
Activity Synthesis (Teacher Notes)
- “Is more than half or less than half of the rectangle shaded?” (More than half)
- “How can you use this to help make your estimate?” (Half of 7 is 321 so it’s a little more than that.)
- “Based on this discussion does anyone want to revise their estimate?”
Standards
Addressing
- 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.