Combinations

Sometimes you look for all the ways things can be combined.
A table helps you to work systematically: every field is one combination.

Example: 2 heads (dotted, striped) and 3 bodies (round, square, pointy).
Go through the table field by field and check off each combination. That way you miss none and count none twice.

You answer the questions with rows and columns: if you write the heads one below the other and the bodies side by side, every row contains as many robots as there are bodies.

Example

roundsquarepointydottedstripedHow many robots have a round body?2

For parents

What does this exercise practice?

Solve combinatorial tasks (number of possibilities) systematically using a table and justify them with rows and columns.

Common pitfalls

Counting freely makes it easy to skip a combination or count one twice. Tip: always go in the same order, row by row.

How to practice at home

At home, combine for example 3 T-shirts with 3 pairs of trousers. How many outfits is that? Does multiplying work?

Related: Certain, possible or impossible?, Number riddles

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