So to review, yesterday I dumped a bunch of rice all over the carpet in my classroom. It was an engaging way to elicit discussion of place value, as they developed strategies to count how much rice I spilled. We settled upon making groups of ten and making ten groups on a piece of paper.
So for Day 2, I drew upon this experience to start out our math day. I put the following on my whiteboard and had my rice gatherers from yesterday partner with the others and explain what we did. Then we filled out the table together. Notice my very unclever drawing of a piece of paper with ten groups of ten pieces of rice.
After we filled this out (this time I chose two people who raised their hand and they passed their whiteboard marker onto another person who had their hand raised), we discussed the patterns we saw and I explained the base ten system of tens and ones. For example I asked what the 1 stood for in the number 13 (10) and what did the three stand for (3), so 10 + 3. I referred to this as expanded notation (this shows up a lot on standardized tests). This took about 15 minutes and then they went to their stations. I dismissed everyone to their station.
I have a group of advanced math thinkers that I sat with. We talked about our number system, based on tens. I asked them what if it was based on sevens. So we talked about the number 23. They figured that the 2 would stand for 2 sevens, so 23 would be 17. Crazy thinking right? But it was super fun.
Here is a link to the basic history of numbers and other number systems. Wouldn’t that be a fun report for students to do? Report on the history of money and then create their own money system? Maybe I can have a group research this, stay tuned.
Thanks for reading!