Sometimes you can combine things in different ways.
A table helps you not to forget a combination or count one twice.
Example: 2 heads (filled, empty) and 3 bodies (round, square, pointy).
Each head fits on 3 bodies, so 2 times 3 equals 6 robots.
Take one head after the other and put it on every body. That way you find them all.
Example
For parents
What does this exercise practice?
Solve combinatorial tasks systematically using a table.
Common pitfalls
Children easily forget a combination or count one twice. Tip: check off the table field by field.
How to practice at home
At home, combine for example 2 T-shirts with 3 pairs of trousers and count all possible combinations together.