DS7, who is HG+ and homeschooled (for those who don't know me yet), had a good day today. I wanted to share my glee with my buddies!
Just for fun, while we were still getting our books out of the car, I asked him a pre-algebra question that he was able to do in his head: x-3=7. Then he asked me about 3-x=7, which led to -x=4, and an excellent conversation about negative numbers and solving algebraic equations. That in turn led to a conversation about negative numbers and exponents, which led to a discussion about numbers so big that they're effectively infinity for normal human purposes--since he wanted to know what 2^100 was, and then he wrote some giganormous number to the gazillionth power. ("I have no idea what that is, kid! It's huge is what it is!"
)
All of THAT led me to tell him the story of the grain of rice on day 1 doubled for every square on a chess board, and we figured that up as far as we cared to (Day 34 or so). Then we talked about rounding, since I did some as we did the math for 2^64. We even did part of a worksheet on rounding that I had printed from that site which someone suggested here on the forum. (I forget who. Sorry to space on the credit!)
All that great stuff took roughly 45 minutes. DS7 was busy and happy and learning the whole time. We flitted around a lot, but the kid can now round numbers no matter how big and to any place, he can multiply negative numbers now, and he can tell with one glance if a negative number with an exponent is + or -.
I call that a good math day! I love those! Happy, happy, joy, joy!
Last winter DS6 spent lots of time calculating 2^ just for fun. I think he stopped around 2^70.
