In the previous activity you estimated the answer to a question about circles.

Create a visual display that includes:

• The question you were answering.
• A diagram of a circle labeled with your estimated measurements.
• Your thinking, organized so that others can follow it.
• Your answer, expressed in terms of and also expressed as a decimal approximation.

Here are two students’ answers for each question. Do you agree with either of them? Explain or show your reasoning.

1. How many feet are traveled by a person riding once around the merry-go-round?

   

   • Clare says, “The radius of the merry-go-round is about 4 feet, so the distance around the edge is about feet.”
   • Andre says, “The diameter of the merry-go-round is about 4 feet, so the distance around the edge is about feet.”

2. How much room is there to put glue on the back of a paper circle?

   

   • Clare says “The radius of the circle is about 3 centimeters, so the space for glue is about  cm².”
   • Andre says “The diameter of the circle is about 3 inches, so the space for glue is about  in².”

3. How far does the unicycle move when the wheel makes 5 full rotations?

   

   • Clare says, “The diameter of the unicycle wheel is about 0.5 meters. In 5 complete rotations it will go about  m².”
   • Andre says, “I agree with Clare's estimate of the diameter, but that means the unicycle will go about  m.”

Your teacher will give you either a problem card or a data card. Do not show or read your card to your partner.