Monday, November 18, 2013

More Math...A Bit of a Soapbox This Time

My kids think I'm a genius because I can do math in my head.   When they were kids looking to spend allowance money and I reminded them they would have to pay tax on an item, the question was always how much?  It always amazed them that I could calculate the tax amount in my head and add it to the purchase price to tell them how much the total would be.  I wasn't always right on the money, but I was usually within a couple of pennies of the actual amount.

 But I'm not really a genius.  I think most people my age can do something similar.  The difference between me and my kids is, I was taught how to do that, they weren't. 

When I do math in my head I do a combination of breaking down numbers and estimating.  Warning....math ahead....Say I need to figure out 6.5% tax on a $53.98 item.  I first round up to $54.00, because really, tax on .02 is nothing, then I break that down to $50 + $4 and I break the 6.5% down to 6% and 1/2%.  From that point there are a couple of ways to figure it out, but here's my most frequent one.  6% of $100 is 6.00, so 6% of $50 (1/2 of $100) is 1/2 of that = $3.00.  6% of $1.00 = .06 (6 cents), so 6 X 4 = 24 = .24 (24 cents), so 6% of $54 = $3.24.  Now that I've calculated that, to get the 1/2% I just have to say there are 12 1/2% to equal 6%, so 1/2% is 1/12 of the $3.24 I've already calculated, and $3.24 divided by 12 is 27, so add another .27 cents and the total tax is $3.51, add that to the original price of $53.98 and you have $57.49. (There's additional estimating I do mentally to add the numbers together, but I've probably bored you with enough math already).

That's a pretty convoluted example, but it gives you an idea what I'm talking about.  And while that took a bit of time to break down for explanation, it doesn't really take as long to do mentally because I don't have to explain it to my brain.

Most of you probably think I'm crazy about now, why not just use a calculator?  But you have to remember, my kids are grown, and phones didn't always have built in calculators.  And if you're over 40, you probably realize that even if you don't use this skill any more, you were probably taught to use the techniques I described above.

So here's my bit of a soapbox.....When did the old way become the bad way?  And why do they keep coming up with new ways to teach math, when it doesn't seem to be helping the kids learn how to do it any better?

My kids came home with math homework that made no sense to me because they seemed to be asking them to go around their ass to get to their brain to get the correct answer.  But heaven forbid they do it another way, because if the part where they "show their work" was different from the way they were trying to teach them it was wrong, even if the answer was correct and you could clearly see how it was achieved.

Now, NC has adopted this "Common Core", which apparently is totally different as well.  My oldest niece is in 4th grade and has done just fine in math until this year when they've apparently changed everything up on her and are telling her to do things differently.  There's some process with boxes and putting numbers in different boxes and I don't even begin to understand it.  Unfortunately, neither does my niece, and since it's totally new my brother and sister-in-law can't help her understand it either.

I admittedly do not not know anything about what "Common Core" involves, and I am not an educator, but no matter what you call it, I think if kids can learn how to do math in a way that comes out with the correct answer, let them do it that way rather than forcing them to learn a way that makes no sense to them.  Not every one's brain works the same. 

And don't even get me started on how early they introduce calculators these days.  I love some technology y'all, but I firmly believe kids need to learn how to do stuff without technology as well.  I mean seriously, what will they all do when the zombie apocalypse comes and all the technology is dead?  Then again, if that happens, maybe doing math will be the least of our worries.

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