Teaching Odds and Evens: Adventures in First Grade Homework
Each month my six-year-old daughter comes home with a “homework menu” - a page that looks sort of like a bingo card but each square has a homework assignment in it. Of the 25 assignments listed, you get to pick 15 to do.
The assignments cover things like, “Write a list of words with a long ‘i’ sound in them” to “Count to 100 by fives.” First grade stuff, no problem. For the most part, she’s got this covered… as long as she doesn’t get off in the weeds.
The other night we did, “Make a list of ten odd numbers.” Easy enough. They’d been learning odds and evens in class, so this shouldn’t be much work. In fact, she finished in just a few seconds, listing all the way from one to 19 in short order.
To help cement the pattern in her mind, I thought I’d show her how all the odd numbers end in 1, 3, 5, 7, or 9. I wrote the numbers in a little table like this so the pattern would be easy to see:
1 11 21 31 3 13 23 33 5 15 25 35 7 17 27 37 9 19 29 39
She got pretty excited about that, then asked the question that took us off the rails.
Phoenix: Daddy, why are they called “odd” and “even” numbers?
Travis: Go grab me like six alphabet blocks from your room and I’ll show you.
She ran to her room, grabbed the blocks, and returned with them bundled in the front of her shirt. She dumped the whole shirt load squarely on my nuts.
Travis (recovering): OK, you know odd numbers, do you know the even ones?
Phoenix: 2, 4, 6, 8, 10.
Travis: Good. Here’s two blocks. [I hold up two blocks.] Is two even or odd?
Travis: Right. If I split that into two even piles there aren’t any left over. [I put one block in each hand and hold them apart from each other.] See that? Two even piles. Now here’s three blocks. [I hold up three blocks in one hand.] Is three even or odd?
Travis: Correct again. If I split that into two even piles… [I put one block in each hand and hold them apart from each other, leaving the remaining block on the arm of the chair.] …then we have an odd man out. That block on the chair is extra. Odd numbers leave an odd man out. Let’s try with four. Is four even or odd?
Travis: OK, and when I split them [I held two blocks in each hand] I have two even piles. Is five even or odd?
Travis: Yup, and when I split them [I hold two blocks in each hand and leave the fifth on the arm of the chair] I have that odd man out. That’s why they’re “even” and “odd.” If it’s an even number, I get even piles when I split it in half. If it’s an odd number, I get an odd man out. Even number - even piles. Odd number - odd man out.
Phoenix: Oh, OK!
Travis: So, let’s review. [I hold up four blocks, two in each hand.] Four is an even number, so when I split it I have… [I pulled my hands apart with two in each hand.]…?
Phoenix: Four blocks.
Travis: Well, I do have four blocks, but we were talking about even and odd. Four is even, right? So if I split it in half, I have…?
Phoenix: Two in each hand.
Travis: That’s true, but I have even piles. Even number, even piles. Five is an odd number [I hold up five blocks in my hands] so when I split it in half [I drop one block on the arm of the chair and hold two in each of my hands] I have…? [I look down at the block on the arm of the chair hopefully]
Phoenix: An extra.
Travis: Yep, but it’s odd so we can remember it easier if we think “Odd number has an odd man out.” If it’s even you have…? [I hide the block on the chair and hold two in each hand.]
Phoenix: Equal piles.
Travis: Uh… yeah, but I really want to know you’re hearing me here, so “Even number, even piles.” Not “equal piles,” but actually the literal words, “even piles.” I need you to say, “even piles.” Sooooo…. Four is even, even numbers have…
Travis (really close to losing my shit): Even numbers, even piles. So, even numbers have…?
Phoenix: Even piles.
Travis: Yes, and odd numbers have…? [I put the extra block back on the arm of the chair.]
Phoenix: Odd piles.
Travis: An odd man out. Odd numbers have an odd man out. Even numbers, even piles. Odd numbers, odd man out. Even numbers…?
Phoenix: Even piles.
Travis: Odd numbers…?
Phoenix: Odd man out.
I think this is going to be a thing with homework this year since last night we ran into basically the same thing.
Travis: OK, Phoe, you need to draw a hexagon.
Phoenix: How many sides is that?
Travis: A hexagon has six sides.
Phoenix: So, five?