This activity is really a series of connected problems. Learners will find that they must complete one part before attempting the next. From each part a 'key' number will be discovered which is required to do the next part of the problem. Accuracy and perseverence will be necessary!
You can download these sheets which divide the problem into its five constituent parts.
You could start by setting the scene and explaining that each part of the challenge 'feeds into' the next. Hand out the first sheet and step back. It would be best for learners to work in pairs so that they are able to talk through their ideas with a partner. When they think they have the first key number, a pair can request the next sheet and so on. You may decide not to give them feedback after each part so that if they reach a sticking point, they will have to check over what they have done so far.
Access to dice, numbered cards $(0 - 9)$ and counters will help some learners tackle the problems.
Allow time for the whole group to come together to discuss their findings and difficulties.
What do you know/what can you discover about opposite faces of a dice?
How will you record what you're doing?
Tell me about what you've done so far.
Have you thought of using numbered cards/dice/counters ...?
Learners could make up a similar 'story problem' for others to do.
Encourage learners to use real dice, numbered cards, counters and anything else they think might be helpful.