There, I said it. And while I’m at it, PacMan is soooooooo 70s! It’s time to move past using alligators for comparing numbers.
There are really two steps involved in comparing numbers. First, students need to understand quantity and determine which number is larger. That’s an exercise in place value and is best handled through lots, LOTS, LOTS! (sorry, didn’t mean to yell…) of concrete practice building and comparing numbers. The second is understanding the symbols: < and >. That’s often more difficult because they are abstract symbols and totally meaningless to children. They understand that one of the symbols means less than and the other means greater than, but they have trouble remembering which is which. Enter the alligator. Yes, yes, the alligator eats the bigger number, and it helps kiddos remember the difference. But there are different, more “mathy” ways for kids to show their thinking in writing. A way that I’ve found works great with students is to put small dots on the symbols. Two dots always face the bigger number and one dot always faces the smaller number, because two dots is bigger than one dot. It’s basically a more dignified version of the alligator method for comparing numbers and takes much less time than drawing teeth.
I heard another great idea today from a fellow math coach. Look closely at the ends of a number line and what do you see? Exactly! The less than and greater than symbols. The 27 is closer to the > symbol and the 18 is closer to the < symbol. She said that she had been working with a second-grade class and they totally saw the connection and were able to use it.
This post generates tons of comments on social media about using alligators for comparing numbers. It’s always great to hear different perspectives, and I appreciate the discussion.