Do you know someone who can do **math** in his/her head? Do you wish you could? This article will show you just how easy it really is to do mathematical calculations without a calculator or pencil and paper.
This may surprise you, but the truth is you're actually *good * at math. Each and every day you solve complex problems by breaking them down into simple steps.
And just like the world's most powerful computer or the greatest ever math prodigy, it's this simple step-by-step process that enables you to do practically anything, including math!
Here are a couple of examples:
** Calculating sales tax**
Sales tax rates vary around the world, but for our example let's say it's 17.5%. Sounds difficult to calculate in your head, right? Well, it isn't...
Let's examine this common math problem and see how we can easily solve it by breaking it down.
17.5 consists of 10 + 5 + 2.5, doesn't it? And those numbers form a distinct sequence. In other words: "10 + half, + half again".
Now that we know this, we can do something very clever...
Suppose you want to calculate 17.5% of 40 dollars. How would you work this out in your head? (And don't even think of reaching for a calculator!)
Begin with the 10. 10% of 40 is 4. Add half (2) and half again (1) and you get 7.
So you proudly announce to your colleagues... "So by adding 17.5% sales tax to our $40 product, the total retail price will be... $47."
They look at you with a look of amazement.
Now, let's examine another example and see just how simple math really is:
** Help your daughter with her math homework.**
You get home and discover that your daughter needs some help with her math homework. It's those darn fractions again. She just can't make sense of them.
"A half times a half is a quarter. So how, when you multiply things together, can you have *less* than you started out
with!"
You explain to her that multiplication and division are simply two sides of the same thing, and you make it "real world" for her with a little analogy:
You instruct her to imagine a cake.
You tell her that "multiplying by half" is another way of saying divide by 2. So she pictures herself cutting the cake in half, giving one piece (half) to her friend Donna, and keeping the other half.
You daughter now has half a cake.
Again, she multiplies her piece by a half (i.e. "divides it into two again") and she's left with a quarter.
She goes off to bed a happy little girl, dreaming about birthday cake, and you get to watch the ball game on TV.
Again, it's all just a matter of simplifying.
Real world math isn't about dread or learning mathematical formulas that you must follow without thinking.
Math is about using common sense, seeing how numbers really work, and breaking math problems down into simple steps.
You just need to use your imagination. After all, that's what
genius really is.
Murdo Macleod is a reformed calculator user and co-author of the 'Fun With Figures' mental math course. Visit him at FunWithFigures.com.
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