I wrote yesterday about a Number Talk I had worked on with my class.
Today I extended that activity by making an array using money. I used the Mathies money tool to display an array made of nickels, then I asked, “What do you see?”
We built this display of our thinking a bit at a time, so I am sure it made more sense to us than it might to you! Someone saw 45 cents. Then someone else saw 15 cents (3x5cents) and then 3 groups of 15 = 45. Some saw the array 3 x 3 = 9 nickels all together. I pointed out 3 x 15 and 9 x 5. Thanks to our work with fact families, a few realized 45 “shared by” 3 people means they get 15 cents each. Seriously! They didn’t just point out that 3×15=45 so 45 divided by 3 = 15. They actually explained what was happening! (Full disclosure: not all of them.)
After this conversation, I cleared the board and made an array using toonies. Now, you might have been expecting me to use dimes, but I thought the $2 coin was better considering that we haven’t talked about multiplying by 10 and my grade 2s would get a lot more out of the conversation if we were thinking about multiples of 2 rather than 10. I will probably give 10s a try tomorrow on their own. After our success today it seems like a good way to get everyone to start thinking about multiples of 10. I’m looking forward to it!