Use a Protractor to Draw Angles
10 min
Narrative
In this Warm-up, students practice estimating a reasonable angle measurement, based on their knowledge of angles so far and their familiarity with clocks. Later in the unit, students will take a closer look at the angles in an analog clock and apply their understanding of angles to solve more sophisticated problems.
Launch
- Groups of 2
- Display the image.
- “What is an estimate that’s too high? Too low? About right?”
- 1 minute: quiet think time
Teacher Instructions
- 1 minute: partner discussion
- Record responses.
- Draw an arc to label the angle that measures 143∘ and show the clockwise turn of the minute hand from the hour hand.
- “Your estimate should show the size of this angle in degrees. If you need to, revise your estimate.”
- As needed, record any revisions.
Student Task
How many degrees is the angle formed by the long hand and the short hand of the clock?
Make an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
- Too low: 0∘– 90∘
- About right: 130∘– 160∘
- Too high: 170∘or more
Activity Synthesis (Teacher Notes)
- Consider asking:
- “Is anyone’s estimate less than _____? Is anyone’s estimate greater than _____?”
- “How did you go about making an estimate? How did you know that _____ must be too low and _____ must be too high?”
- “Based on this discussion, does anyone want to revise their estimate?”
- Consider revealing the actual measurement: 143∘.
Standards
- 4.MD.5·Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
- 4.MD.C.5·Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
15 min
20 min
Knowledge Components
All skills for this lesson
No KCs tagged for this lesson
Use a Protractor to Draw Angles
10 min
Narrative
In this Warm-up, students practice estimating a reasonable angle measurement, based on their knowledge of angles so far and their familiarity with clocks. Later in the unit, students will take a closer look at the angles in an analog clock and apply their understanding of angles to solve more sophisticated problems.
Launch
- Groups of 2
- Display the image.
- “What is an estimate that’s too high? Too low? About right?”
- 1 minute: quiet think time
Teacher Instructions
- 1 minute: partner discussion
- Record responses.
- Draw an arc to label the angle that measures 143∘ and show the clockwise turn of the minute hand from the hour hand.
- “Your estimate should show the size of this angle in degrees. If you need to, revise your estimate.”
- As needed, record any revisions.
Student Task
How many degrees is the angle formed by the long hand and the short hand of the clock?
Make an estimate that is:
| too low | about right | too high |
|---|---|---|
Sample Response
- Too low: 0∘– 90∘
- About right: 130∘– 160∘
- Too high: 170∘or more
Activity Synthesis (Teacher Notes)
- Consider asking:
- “Is anyone’s estimate less than _____? Is anyone’s estimate greater than _____?”
- “How did you go about making an estimate? How did you know that _____ must be too low and _____ must be too high?”
- “Based on this discussion, does anyone want to revise their estimate?”
- Consider revealing the actual measurement: 143∘.
Standards
- 4.MD.5·Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:
- 4.MD.C.5·Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement: