Problem Solving Prompts

Learning Goals:

  • Estimate and record the mass of objects
  • Determine the missing numbers in equations
  • Investigate variables as unknown quantities

The Challenge:

Liu came across some sports equipment when she was cleaning up and thought it might be fun to weigh some of it.
She recorded the following measurements:

Three equations combining the mass of sports equipment. First is baseball plus soccer ball equals 530 grams, second is baseball plus baseball equals 280 grams, and third is soccer ball plus basketball equals 890 grams.

What is the individual mass of each ball?

Imagine Liu was packing a gym bag containing three baseballs, a soccer ball, and two basketballs. What would be the total mass of the equipment? What would this mass be in kilograms?

Questions and Prompts to Support your Child:

  • Which type of ball did you figure out the mass of first? Why did you start there?
  • How do you know that those masses work for each type of ball?
  • Could knowing any of these masses help you estimate the approximate mass of any other common objects? A Tennis ball? A glass of water?

Extensions & Adaptations:

  • If struggling with calculations, have a calculator handy!
  • If unable to get started, try looking for equations containing only one type of equipment (two baseballs have a total mass of 280 grams.)
  • Check out Mashup Math or SolveMe Mobiles for some more algebraic puzzling!

Source: University of Waterloo – CEMC Problem of the Week Database