One to Fifteen

Problem | Teachers' Notes | Hint | Solution | Printable page |
Stage: 2 Challenge Level: Challenge Level:1

Why do this problem?

This problem is a good one for teaching what consecutive numbers are and learning to spot them. It is fun to do as long as there are real objects, such as numbered counters, to move around or an interactivity to use.

Sound logical thinking is required but, almost inevitably, some trial and improvement will also be needed!

This photocopiable sheet might be useful but numbered counters will still be necessary.

Key questions

Which circles lie on the fewest straight lines? How might this help?
If you try putting the number $1$ on one circle, where could you put the $2$? Now, where could the $3$ go?
Which numbers have fewer consecutive numbers than the other numbers?
If you have $12$ down, for example, which numbers are consecutive to it?

Possible extension

Learners could be challenged to find as many different solutions they can.

Possible support

Suggest using the interactivity if at all possible as this identifies the consecutive numbers.

Published January 2007.