Odd and Even
Why do this problem?
This problem is designed to help young children to create a proof that two odd numbers added together always give an even answer. This is very different from deriving general proof through exploring different cases.
Possible approach
It is worth spending time exloring a numbers of cases and you might like to do this by following through the ideas below.
You could start by getting the whole group to count in twos. Repeat but starting with one, so the odd numbers are counted.
Next you could show the group how to draw the numbers in twos on squared paper to show the "odd one" sticking out or an "even" top. It is better if they can cut out the various numbers because these can then be turned over. Alternatively the children could make models using Multilink or Numicon.
At the end of the lesson the group could come together again to discuss their findings and show their work.
Key questions
Is this number odd or even? How do you know?
Try counting in twos. Does the number come up?
Why not draw it on the squared paper and see if there is an odd square sticking out?
Possible extension
Learners could make larger numbers. Alternatively they could do this problem picturing numbers in a different way Numbers as Shapes or even try this stage 2 problem, Number differences.
Possible support
Suggest cutting out the numbers from 1 to 10 from squared paper and numbering each square. (2 cm squared paper would be best for this.) Some children may need help with the actual cutting.