## Saturday, February 11, 2012

### Odd and Even

Day 1: Object pairs

Prep: Give each student a copy of the Object Pairs worksheet, a pencil, and a small bowl of beans. (Beans can be shared with a neighbor.)

Lesson: Teach students that odd numbers end with 1, 3, 5, 7, 9 and even numbers end with 0, 2, 4, 6, 8. Emphasize that it's only the number in the ones place that matters when deciding whether a number is even or odd. Review tally marks.
Teach students that if a number is even, it can be divided into pairs. If it's odd, dividing into pairs will leave one loner left over. Ask students to grab a small handful of beans and determine whether it's even or odd by this method, then count the number of beans to see if they were correct according to the rules. (Demonstrate before turning them loose.) Have students do this several times and keep a tally of how many even versus odd numbers they come up with.
Have students leave the table (and the beans!) and sit in a circle on the floor. Teach students that there are sometimes patterns to the even and odd numbers around us. Bring books for each student and ask them to open to a random page. Go around the circle and ask if the even page number is on the right side or the left side. Which side is the odd number on? Is it the same for all books? (Yes; books always start with page one on the right side, so all the odd numbered pages end up on the right.)
Ask students what the number is on their house. Is it even or odd? Ask them to go home and look at all the house numbers on their street and which side of the street they're on. Is there a pattern? Hand out odd and even reminder cards for students to take home.

Day 2: Even Steven and Odd Todd

Prep: Give each student a copy of the Even and Odd/200 chart page.

Lesson: Follow up on house number homework suggestion. Did they notice a pattern with house numbers? (Even numbers are on one side of the street and odd numbers are on the other.)
Review that odd numbers end with 1, 3, 5, 7, 9 and even numbers end with 0, 2, 4, 6, 8. Review tally marks.
Read Even Steven and Odd Todd (or fun facts from a book like National Geographic Kids: Weird but True). Ask students to put a tally mark in the even or odd column of their page whenever they hear an even or odd number. Which were there more of in this book?
Tell students that there is one number that isn't even or odd. Ask them to fill out the hundreds chart using ONLY EVEN NUMBERS. Students should start with 2 and reach 200 by the end. Then instruct them to color in the numbers written at the bottom of the page to find out the only number that's neither even nor odd. (The answer is ∞ , the symbol for infinity. We actually talked about this one day for reasons I can't remember, so it might be familiar to some of them.)