Hey math dorks, question.
So, 9-year-old is onto the Pythagorean Theorem. Hooray. Issue: the software she uses is having her do these problems where it gives her 6-digit numbers she needs to take the square root of. They're perfect squares, but the whole thing seems really tedious to work them out.
So... I busted out the calculator. Any reason not to?
Them being perfect squares is a bummer: that teaches that correct solutions are neat and round, which isn't really a good heuristic (and is somewhat subtly distinct from the "simple conceptually" heuristic, which IMO is good).
I'd also consider showing the 9-year-old a slide rule and explaining how one can use it. I'm not too sure about it though (on one side: neat device, gives intuitions like "square root will have half as many digits", requires manual sanity checking; on the other might seem magical for someone who doesn't have the concept of a logarithm).
