Teaching kids real math with computers/calculators

[burkhard]

(08-26-2018 03:46 PM)Albert Chan Wrote:  I think teaching math with calculator or a computer is a mistake.
Students need to be able to do it in their head.

Only *after* that step is solid, should calculator is used (to save time)

One time I was in a supermarket, the cash machine was broken.
The cashier math skill were so bad, the change I get back is *more* than I paid her !

Our four kids are homeschooled and even for the eldest (entering 6th grade) calculator use is really limited to only "special" activities that occur on occasion. We want fluid numeracy in head, with requires some rote learning of things like the multiplication tables. There's really no way around it, I think.

Albert's story was funny. I have another. A few years back, I was at the local home center store which has a gardening department. It was late in the summer and the remaining plants had been marked down once already and that day were getting another mark-down as the store attempted to clear out the seasonal inventory. I attempted to buy several shrubs which already had been marked "50% off" their original price. That day there was a sign out among the plants which said "starting today, reduced another 50% !"

Well I took the shrubs up to the counter and the cashier (late teens, early 20s, not long out of school herself) was completely flummoxed. She kept telling me that couldn't be right because it would mean I'd be getting the items for 100% off. She had the calculator out and sure enough, 100% off meant everything was free! I desperately tried explaining to her how percentages worked, but she eventually needed a manager.