How large number can we reach together?

First day:

1. Instruct the pupils to walk or bike to school the next day, if possible. Otherwise, a short outdoor visit could do.
2. Instruct the pupils to collect numbers on their way, such as number of black cars, animals, or bikes.

Second day:

1. Ask the pupils to write down their numbers.
2. Collect the pupils’ numerical observations. These can be listed within different categories or just all numbers together on a blackboard/whiteboard.
3. Describe the concepts of even and odd numbers. Exemplify with numbers on the blackboard.
4. Instruct the pupils to think about which of the other numbers on the board that are even and odd.
5. If you find it appropriate, you can continue to present the concepts of half and double, and exemplify with some numbers on the board. Then, you may ask the pupils, for instance: ”How many bikes would you have seen if you saw the double?”
6. Depending on the mathematical levels of the pupils, you may ask about the sum (or, more advanced, the arithmetic mean) of the numbers, or you can demonstrate the calculations before them. Each number counts, so each pupil’s number helps in getting the number larger.
7. Evaluate together by asking how the pupils think that the activity went, what they felt and thought about doing the different parts, etc. During this phase, you can ask the pupils if they would like to do the exercise again during the next math lesson, and then you may encourage the pupils to decide individually what kind of numbers they should collect (small numbers, large numbers, only odd numbers, primes, etc.). You could also choose this democratically with the main idea that all pupils collect the same kind of numbers. If you choose to let the majority decide what numbers all should collect, just remember to have a ”way out” for the ones that find the majority’s decision too difficult or too simple.