Share Bears
Problem
Can they share one bear equally? Can they share two bears equally? Three bears? Four bears...?
What do you notice about the numbers they can share fairly? It might help to look at a number line and mark the numbers that do share fairly onto it. Do you notice a pattern?
How about using a 100 square?
Printable NRICH Roadshow resource.
Getting Started
Find some teddies so you can share different numbers of them with a friend. If you haven't got any teddies, you could use something else like counters, other toys... anything!
How will you check if that number of teddies has been shared equally?
Student Solutions
Thank you for all your correct solutions to Share Bears. Natah from Claremont Fan Court School, Marcus from St Philip's School and Halo from Arden Primary School, Australia were able to find a general pattern. Here is what Halo wrote:
Yasmin and Zach can share a number 2, 4, 6, 8 or 10 bears between themselves. I noticed that all these numbers were even. I think this is because the bears are shared between 2 people, so only multiples of 2 can be shared between them.
Teachers' Resources
Share Bears
Can they share one bear equally? Can they share two bears equally? Three bears? Four bears...?
What do you notice about the numbers they can share fairly? It might help to look at a number line and mark the numbers that do share fairly onto it. Do you notice a pattern?
How about using a 100 square?
Printable NRICH Roadshow resource.
Why do this problem?
Possible approach
Bring the class back to talk about their findings. You could shade the numbers they have managed to share on a hundred square and then use this as a basis for discussing these special even numbers. Can the class predict what the next even number will be? How do they know? What is the largest even number on the hundred square? How do they know?
Key questions
Show me how you are deciding.
How do you know whether that number of teddies has been shared equally?