Roll These Dice

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

Why do this problem?

This activity offers practice in addition and subtraction, including negative results, but the main aim is for pupils to concentrate on making sure that all the ways of rolling the three dice are reached. This will need some sort of system and you could focus on how this could be recorded.

Possible approach

You could introduce the problem using real dice and modelling the calculation a few times so that pupils get a feel for it. Once a few results have been recorded on the board, invite the pupils to speculate on how many different results there might be.

Ask them to work in pairs or small groups on the problem, saying very little else at this stage, but after a short time, get them together again to share insights so far. Discuss the range of answers that learners have found up to that point and make sure they are happy with subtracting one number from a smaller number. (Using a number line which includes negative numbers might be helpful at this point.) Invite some pairs to describe how they are working. Some may be throwing real dice, others may be listing numbers. Encourage some sort of system so that they can be sure no results are left out. You could ask children to suggest ways of recording which would help - this could be in the form of a table or chart, but allow pupils to choose a way that suits them.

Key questions

What are all the different possibilities that you found?
What are the final answers by doing the addition and subtraction each time?
Is there a good way of making sure you find all the possibilities?
How will you record what you've found out?

Possible extension

Those children who are beginning to use the probability scale from $0$ to $1$, could begin to quantify the likelihood of getting particular results. Asking and investigating 'What if ...?' questions would be another good follow-up activity.

For the highest-attaining

Pupils can be challenged to use multiplication as well as addition and subtraction and then after some experimentation try to predict totals that will NOT be possible, then check these preditions out as well as explaining the preditions.

Possible support

It can be helpful for dice to be available, should children need them for reference. Some pupils will benefit from an adult working alongside them and asking questions along each step of the way until their confidence has increased.


Published October 1998.