- Topics: History of Math, Mathematicians: Mathematicians Are People, Too: Stories from the Lives of Great Mathematicians (Volume One) by L. Reimer and W. Reimer, Chapter 5 (John Napier).
- Topics: Multiplication, History of Math: I printed out one set of Napier’s Bones per kid. I showed the kids how to use them to do multiplication of a large number by a single digit number. A follow-up that we didn’t do this time is to use the bones for multiplying two large numbers.
- Topic: Sorting: The kids attempted to sort cards with all numbers from 1 to 300.
How Did It Go?
We had four kids this week.
The kids liked the (non-mathematical) stories about John Napier and the rooster and John Napier and the pigeons. We’re now thankfully past the part of the book where the mathematicians all die at the end of the story.
The kids understood how to use the bones fairly quickly. One of the kids is very good at paper-and-pencil multiplication, so while I could slightly win on large number X single digit multiplication, the other kids couldn’t. I showed them why it worked (see second picture above). The place where the bones really shine is multiplying two large numbers, since you can use the same arrangement of the bones for each single digit multiplicand, so we should do that race at some point.
Sorting to 300
The kids decided to use labels, this time making sure to have labels bigger than 200. It took them 10-15 minutes to make the labels, so next time I’m going to count this time as part of the overall time. In particular, they didn’t think of simply using the cards that were multiples of 10 as “labels”. They went with the same strategy of running back and forth even though I tried to get them to come up with something better; our daughter said that she WANTED to run back and forth so she could get some energy out. I let them go for 17 minutes (which meant that circle went over by ten minutes), and then got 200 of the 300 cards sorted. One of the kids was feeling tired and decided to first find all the numbers between 1-100 and do those first, since that required less running. If only more of them were lazy…