Carrying Cards

Carrying Cards

These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it.

Each child in blue is holding a number which is four more than the child in the same row wearing red.

The children in yellow shirts each have a number which is double the number of the child in the same row wearing red.

Some of the numbers that the children in red, blue or yellow shirts are holding have got rubbed off. What should the numbers be?

Can you work out how the numbers that the children in green are holding have been worked out? What are the two missing numbers?

If there was another row of four children standing behind the fourth row, what numbers would they be holding?

Why do this problem?

This problem will give pupils experience of looking for, and explaining, number patterns, and it could lead into algebra. It would also make a good introduction to spreadsheet use.

Possible approach

You could introduce this problem practically in the classroom with children holding small whiteboards, for example. Rather than wearing coloured shirts, the children could have particular coloured pens or they might wear 'bibs' or ribbons usually used for sports matches. Arrange the sixteen children in four rows of four as in the picture and write the given numbers on the appropriate whiteboards. Once the problem has been introduced in this way, the sixteen children can return to their seats and the whole class can discuss the challenge. Learners should be given time to talk to each other in pairs or small groups as well as discussing the problem as a whole class. 

Key questions

Possible extension

Possible support