The purpose of this activity is to help your child to see that you can count the same number of items in different ways and reach the same sum.
Link to NZ Curriculum:
Your child is learning the counting sequence to 100, is learning to count in 2s, fives and tens, and is developing an understanding of equal grouping. (This is laying a foundation for multiplication).
What you need:
- A collection of shells (or leaves) of different kinds, sizes, shapes and colours
- Pencil and paper
What to do:
- Have your child make a pile of approximately 20 shells in front of them.
- Ask them to count these one at a time and then repeat this to make sure their count was correct. (Check they are counting one-to-one accurately)
- Ask, “Can you count them a different way?”
If necessary model and support then to make groups of two, and count 2,4,6,8,10... Notice together that the total is still the same.
(Talk about what to do if there are an odd number of shells.)
- Ask them how many pairs (groups of 2) they have. Together notice for example, ten groups of 2 is the same as 20 shells.
- Repeat this with groups of five, counting 5, 10, 15, 20.
- Combine 2 sets of five to make ten and count, 10, 20.
- Have them add more shells to their pile and repeat the activities above.
- Pose other questions/problems such as:
Can you think of other things we could count in twos? (people’s eyes, legs, arms, thumbs, eggs in a carton), in fives? (the fingers on people’s hands, and toes), in tens? (total number of fingers and toes per person).
Are there other ways that your could count them (eg. in threes, in fours).
Can you think of a way you could write down what you have done?
- Encourage equations such as 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 20. (In checking that they have recorded ten 2s, they are reinforcing the understanding that ten groups of 2 is the same as 20.
Mathematics language/vocabulary that you are developing with your child:
- groups, equal same, total, sum
What to expect your child to do:
- Form groups with the same number in each (equal groups).
- Count accurately in ones, twos, fives and tens
- Know how to add ‘remainders’ if the number chosen is odd.
- Accurately record simple addition equations.