Different Names for a Number

Hi! I'm Jenny of Luckeyfrog's Lilypad, and I am super honored to stop by while Casey enjoys her vacation! Thanks, Casey, for letting me be a Math Maniac for a day!

One of the activities we do from time to time in my math class is "Different Names for a Number." I always introduce it by saying that I have different names. The kids call me by my 'teacher name,' but my husband calls me something different, and some of my friends have funny nicknames for me too (I always tell them at least one, which cracks them up).

I ask them to share if they have another name. There's usually a Michael that goes by Mike, or some other nickname that works perfectly. And then we discuss how Michael and Mike aren't suddenly different people- it's the same person, just being called something different.

Well, I tell them, numbers are the same way!

 25 can be expressed as 20 + 5, two tens and five ones, twenty-five, 25 ones, a quarter, 1/100, 75 - 50, two and a half ten frames... the list is endless. And really, they're all the 'same' number- just with different names! And it's so good for kids to think about numbers this way.

My students loved being handed a big piece of construction paper (or chart paper) and markers, and given a time limit to find as many names for a number as they could. We did this a few times at the beginning of the year (which really helped me get a feel for their number sense!), and then occasionally thereafter. They really liked when I connected it to special occasions, like 100 Day (seeing if we could find 100 names for 100!) and my birthday (different names of 25, my age). (Yes, I'm a baby.) When we're not working in groups, I have students brainstorm for 1-2 minutes in their math notebooks, and then share with the people sitting near them.
 

The great thing about it is that it forces kids to think about what a number really means, and connect many of the different ways we learn about numbers. When a kid writes "sides of a square" as another name for 4, I know they're really drawing connections. And it's a self-differentiating activity- because the kids are trying to come up with something no other group will, they push themselves to think of something new at whatever level they are. In 2nd grade, most of my students were focused on addition and subtraction names. In 3rd grade, with the same activity, I will hopefully see more multiplication, and division.

You can even challenge them to find all of the "addition" names for a number, and see if anyone picks up on a pattern. For instance, the addition names of '4' would be:

4 + 0
3 + 1
2 + 2
1 + 3
0 + 4

And then ask if they are sure that's all of them, and how they know. (Only a few of mine picked up on the pattern before the others mentioned it- you can see one below!)

This is a great little 5-10 minute time filler, once they know how to do it. Easy, valuable, and quick? Yes, please! Great for pre-assessment at the beginning of the year, and even a quick bulletin board in a pinch? Definitely my style.
 

For more about our math notebooks (and a freebie!), check out my blog, Luckeyfrog's Lilypad. I taught 2nd grade this past year and will teach 3rd this coming year, and as a pretty new teacher, I try to keep things simple but meaningful as much as possible!

Thanks again, Casey!