Make 37

One way to start is to ask pupils to make 16 using any 4 of the numbers. They will quickly find a variety of answers. Declare this is too easy and set them on the task of making 37 using 10 of the numbers. Make sure they have paper for working on. Then give the pupils time to "play", trying out different numbers for themselves. It would be a good idea to encourage them to check their results with a neighbour! Refrain from asking if it is possible; wait till a pupil suggests it can't be done. To which the response could be: "Why can't it be done?" It might be appropriate to ask pupils what numbers they HAVE been able to make and what they notice about these totals. Turning pupils' attention to the properties of the numbers that are possible will encourage them to suggest conclusions. Have they noticed that all the totals are even? This may alert them to the fact that making 37 is much harder than they thought or does not seem to be possible. You could invite them to share their thoughts using the following prompts: * Can you make 37 with a different number of numbers? How many? * Can you explain why? Drawing diagrams of odd and even numbers may help pupils to visualise the mathematics. A follow-up question along the lines of "How could you change the problem so that we can make 37 from ten numbers?" provides a useful opportunity to gauge how fully the children have understood the ideas. This problem could be used as a starter before tackling the more challenging Take Three from Five