You may also like

Prompt Cards

These two group activities use mathematical reasoning - one is numerical, one geometric.

Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

Sisters and Brothers

Age 7 to 11
Challenge Level

Cassandra, David and Lachlan are brothers and sister.
They range in age between $1$ year and $14$ years.
Can you figure out their exact ages from the clues?

Lachlan's age and David's age added together is $10$ years.
Cassandra's age and Lachlan's age added together is $15$ years.
David's age and Cassandra's age added together is $19$ years.

This problem was made up and sent in by Cassandra from Cambridge in the UK. Thank you Cassandra!