Tuesday, September 16, 2008

Dan and math

Dan asked me, "What's 95 plus 80?"


"Yay! I got it right! Andy asked me what it was and I figured it out!" (Andy has been quizzing Dan lately -- no idea why)

"How'd you get that answer?"

"Because I know 100 plus 80 is 180, and 75 is 5 less than 80, then 95 plus 80 is 5 less than 100 plus 80."

He spent the next half-hour figuring out math sums on his own, and telling me how he came up with them.

"Mom - 28 plus 28 is 56!. Know how I did that? 20 plus 20 is 40, then 41, 42, 43, 44,.... (up to 56 on his fingers)."

"You added the ten-units, then counted up the one-units. Cool!"

"No, I added the 20-units, then counted the other 16." (very matter of factly)

Which prompted me to give him a quick description of place values as a math concept.

Even cooler, it's all math done in his head!

He is too clever!

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