Timer

Act 1

1. How much time is left?

2. Write down a guess.

Act 2

3. What information would be useful to figure this out?

4. Write down some questions you have in your head right now.

Here is the link to a handout with the image for students to measure.

Also, if paper isn’t ideal, here is the link to a GeoGebra applet for students to work with.

Act 3

Sequel

5. If a 55° central angle represented 24 seconds remaining, then what was the original timer set for?

STandards

Common Core

• 7.RP.A.2 - Recognize and represent proportional relationships between quantities.

TEKS

• 7.4(D) - solve problems involving ratios, rates, and percents, including multi-step problems involving percent increase and percent decrease, and financial literacy problems