Grade
3

Math in Our World: Pet Races

Dogs Coda and Baxter race in the yard.

Coda and Baxter love to race to the gate in our fence. They both run really fast. Sometimes Coda wins the race. But sometimes Baxter wins.

The gate is 24 feet from the back door. It takes Baxter more leaps to get there than it takes Coda. Baxter’s leaps are always the same length. Usually Coda’s leaps are the same length, but sometimes they are different lengths.

  1. Use pictures, models, or numbers to show what is happening.
  2. What do you notice? What do you wonder?
  3. What mathematical questions can you ask about this situation? Answer all the questions you can!
  • Draw and label a number line to show the information you know. Include each dog’s leaps.
  • How many leaps might it take each dog to get to the gate?
  • What if Coda takes 6 leaps to reach the gate and Baxter takes 8? What is the distance of a single leap for each dog if Coda’s leaps are the same length?
  • Show your work to someone else and explain your thinking. Did they understand?
  • Ask if they have any other questions you can answer!

Find all of the lengths Baxter’s leaps could be. How can you tell if you have found them all?

Set up a start and finish line somewhere safe at your home. Measure the distance between the lines. Challenge a family member to hop from start to finish, and you do the same. How many hops did it take each of you? Who had fewer hops? Why? What’s the length of one of your hops?