Why do this problem?
allows children to do addition and subtraction, and compare numbers in an interesting and challenging setting. They will be encouraged to develop skills linked with reasoning about numbers while engaging with the problem. It is a good opportunity to talk about working through combinations
systematically and ways of recording this.
might be useful for both working on the problem and recording. The numbers in each of the rooms will have to be put in by children themselves.
Can you go through all the numbers?
Which is the best number to leave out?
How any spells do you collect going that way?
Would it help to record the routes you take so that you do not repeat yourself?
Can you find a route that collects more/less spells?
Is that route exactly $35$ spells?
Children could find how many different ways there are to go down the tower or put in different/harder numbers on this sheet
. Alternatively they could try Getting the Balance.
Suggest using simpler numbers such as only one and two on this sheet
. Counters representing the spells could be used on the sheet or a rough picture of the problem.