Picture of a pile of gummy bears in a variety of coloursInvestigations

Materials:

  • paper
  • pencil
  • 20 small objects (e.g., pebbles, coins, popcorn kernels)

Michael has a bag of gummy bears. The total number of gummy bears is not higher than 20.

He counts the gummy bears using groups of two. He has one left over.
Then Michael counts his gummy bears using groups of five. He has 2 left over.

How many gummy bears could Michael have altogether?
Can you find another answer?

Guiding Questions:

Which numbers of gummy bears will have one left over when they’re grouped in twos?
How could you find out which of these will have two left over when they’re grouped in fives?

Possible Extension:

You could ask what numbers of gummy bears this would work for if there were more than twenty.

Adapted from nrichmaths.org