standard_description: Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
problem_activity: Narrative
The purpose of this Estimation Exploration is for students to use their experience with the number line, decimals, and fractions to estimate the value of a number located on the number line. Students may answer with a fraction but are likely to write a decimal since they have been working with decimals for the last several lessons. In the synthesis, students reflect on how having tick marks for each tenth would help improve their estimate.
Launch
Groups of 2
Display the image.
“What is an estimate that’s too high?” “Too low?” “About right?”
1 minute: quiet think time
Activity
“Discuss your thinking with your partner.”
1 minute: partner discussion
Record responses.
Student Facing
What number might be represented on the number line?
[IMG]
Record an estimate that is:
|                    too low                     |                  about right                   |                    too high                    |
|------------------------------------------------|------------------------------------------------|------------------------------------------------|
| \(\phantom{\hspace{2.5cm} \\ \hspace{2.5cm}}\) | \(\phantom{\hspace{2.5cm} \\ \hspace{2.5cm}}\) | \(\phantom{\hspace{2.5cm} \\ \hspace{2.5cm}}\) |
Student Response
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Activity Synthesis
“Would having tick marks for each tenth on the number line help improve your estimate? Why or why not?” (Yes, because I could see if it is one of the tenths and if not, where it is relative to those numbers.)


aligns: no