Mo has left, but Meg is still experimenting. Use the interactivity
to help you find out how she can alter her pouch of marbles and
still keep the two pouches balanced.
Age 11 to 14 Challenge Level:
Meg and Mo are playing Marbles together. After each game, they each put their marbles in a pouch and hang the pouches on a balance while they go off for a snack. You can use the interactivity to experiment to help you answer the questions below.
After their first game, they each have the same number of marbles. Meg puts hers in the pouch 50cm to the left of the centre, and Mo puts hers 50cm to the right of the centre. Using the interactivity, you can check that this balances.
Suppose that when they come back, Meg moves her pouch to be 80cm away. Find where Mo must put her pouch so that it still balances.
If Meg moves her pouch to be 25cm from the pivot, find where Mo must put her pouch.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice.