1_12_07

Re-visit the "Can everyone have a partner?" problem.

Have index cards with numbers of students on them. Students get a card and solve whether everyone can have a partner or not if there are that many students. Include numbers 1-20 and then other numbers. If a student finishes his or her card, they get another card (there are more than 1 per student).

When students return to share, start with the number 1. The student who had that card shares his or her answer. Cover the number 1 on the hundreds chart with a green overlay. Go to the number 2, and since it is an even number, cover it with a red overlay. Talk to the students about how numbers where everyone does have a partner will be red and numbers where everyone doesn't have a partner will be green.

See if students begin to notice a pattern. See if they can figure out other random numbers and whether everyone would have a partner. Introduce the words //odd// and //even//.

If there's time, work on a chart that has this data:
 * 1) how many students there are
 * 2) if everyone can have a partner
 * 3) how many pairs there are
 * 4) how many extras there are (it will always be 1 for odd numbers and 0 for even numbers)

Again, talk about patterns they notice.