1. The case of the Missing Sock

2. Goal:
To be able to explain the difference between odd and even numbers as well as predict and clearly explain when odd or even numbers result from mathematical operations such as adding and subtracting.

3. Socks are best in pairs! How many socks are in a pair?
If you have 2 pairs of socks how many socks do you have?
If you have 3 pairs of socks how many socks do you have?
If you have 12 pairs of socks how many socks do you have?

4. Socks are best in pairs!
Write a sentence that explains how to find the number of socks you have given the number of pairs you have.

5. Socks are best in pairs!
If you have four white socks, how many pairs do you have?
If you have ten white socks how many pairs do you have?
If you have four white socks and six blue socks how many pairs do you have?

6. Socks are best in pairs!
Write a sentence to explain how to find the number of pairs of socks you have given some socks that are the same color.

7. Socks are best in pairs!
If you have 3 socks how many pairs do you have?
What’s going on…?

8. Odd and Even Numbers
Putting socks in pairs helps determine if you have an even number of socks or an odd number of socks.
If you have one sock leftover, you must have an odd number of socks.

9. Put the socks in pairs to see if we have an even or odd number of socks by clicking and dragging the socks

10. Socks are best in pairs!
Do we have a missing sock? Explain why…

11. Odd and Even Numbers
In general, a group contains an even number of items if it can be divided into two groups.

12. Odd and Even Numbers
In general, a group contains an even number of items if it can be divided into two equal groups.
8 stars can be divided into TWO equal groups of 4 stars

13. Odd and Even Numbers
In general, a group contains an odd number of items if there is one left over when you try to divide the group into two equal groups

14. Odd and Even Numbers
In general, a group contains an odd number of items if there is one left over when you try to divide the group into two equal groups
9 stars cannot be divided equally into two groups
without having 1 star left over

15. Odd and even Numbers Let’s take a closer look at odd and even numbers…
(Excel sheet…)