Choose three students to act out the scenario with a (real or
imaginary) pot of $40$ counters, as described under support
below.

Ask students to work in pairs or small groups to try and find
the answers. If any groups are successful too quickly (!) ask them
to change one or more of the fractions, and to adapt their
strategies to the new situations.

As a group discuss the methods used.

What worked? What didn't work?

If faced with a similar problem in future, which methods would the class use?

What worked? What didn't work?

If faced with a similar problem in future, which methods would the class use?

Methods students have used include:

- trial and error, making strong use of the upper bound of 40,
- working backwards from the fact that they end up with the same amount.
- focusing on one individual child's initial share of counters
- use the fact that each child passes a certain fraction to their neighbour.
- algebraic representation

Because the problem has many variables, students will need to
devise a clear recording system

Can Ben start with $10$ counters?

Why can't they use all $40$ counters in this game?

What are the possibilities for Emma's first pile of
counters?

What possible numbers of counters could each child end up
with?

Will there be just one solution? No solution? Many
solutions?

Change the numbers. What if the $40$ were $100$, or a
limitless supply of counters?

What if the third, quarter and fifth were different fractions
- unitary or not?

What generalisations can you find in the solutions?

Group students in $3$s and provide sets of $40$ counters. Ask
them to play this game as a group and challenge them to be the
first group to find the answer. Use these rules

- Decide who will be Emma, Jack and Ben.
- Emma chooses any number of counters from the $40$ counters and notes this number down
- Jack then chooses any number of counters from those left over and notes this number down
- Ben then chooses any number of counters from those left over and notes this number down
- Emma, Jack and Ben then find a fifth, quarter and third of their counters respectively
- All pass the counters to their neighbour
- If they all have the same number then the group has won.

As students try to play this game they will encounter
difficulties in making the fractions and see that the number of
counters taken must be quite specific in order to end up with the
same amount at the end. Students should be encouraged to learn from
their mistakes to try to find out the winning combination.