### Domino Sorting

Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?

### Sort the Street

Sort the houses in my street into different groups. Can you do it in any other ways?

### Shapes in the Alphabet

In this problem, we're going to find sets of letter shapes that go together.

# Sorting Numbers

##### Age 5 to 7 Challenge Level:

Samantha from Kaleen Primary School wrote:

1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49
My group is all odd numbers from 1 to 50

Molly from Worfield Primary sent in some different sets:

Odd Numbers between 0 and 25 (half of 50):
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 and 25.

And Even Numbers between 25 and 50:
26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48 and 50.

I wonder if "between" is the right word to use here? What do you think?

Alex from Sprowston Juniors and Yale from Randwick Public School offered similar sets. Here is Alex's:

Prime Numbers up to twenty: 2, 3, 5, 7, 11, 13, 17, 19

And Yale's:

1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 - they are all prime numbers between 1 and 50

Again, perhaps "between" isn't quite right?

Finally, Roxy from Burrowmore Primary found a different way of sorting the numbers. She says:

We think you should have 2 boxes.
1. Numbers with a curve in them: 0, 2, 3, 5, 6, 8, 9, 10, 12, 13, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 42, 43, 45, 46, 48, 49, 50
2. Numbers without a curve: 1, 4, 7, 11, 14, 17, 41, 44, 47

You could link this to venn diagrams and even have numbers with both curvy and straight lines!

What a good idea, Roxy!