# 4 Simple Math Hacks They Don’t Teach You In School

Almost forty percent of students (that reported it) hate math. Why? The idea behind math should be straightforward, but a lot of people get mixed up in the numbers.

And the formulas, A equals what times what? It’s pretty much greek. But not with these math hacks, they’ve got your back.

Learn how to make your life easier below.

## I. Multiples of Nine

When it comes to multiplying by nine, the trick we were taught in my class was to multiply it by ten and subtract nine. That’s not always so time efficient.

Instead of rounding up to ten and then doing subtraction, just use this simple tip.

Write down, on a side sheet, 9 x 1, 9 x 2, all the way up to ten. Now draw all the equal signs but DON’T do the calculations. Instead, write 0 through nine right next to the equation sign.

So it looks like:

• 9 x 1 = 0
• 9 x 2 = 1
• 9 x 3 = 2
• 9 x 4 = 3

And so on until you hit 9 x 10 = 9.

Once the first column is done, go back up to 9 x 1 = 0 and count down from nine. So it’ll looks like:

• 9 x 1 = 09
• 9 x 2 = 18
• 9 x 3 = 27
• 9 x 4 = 36
• 9 x 5 = 45
• 9 x 6 = 54
• 9 x 7 = 63
• 9 x 8 = 72
• 9 x 9 = 81
• 9 x 10 = 90

When you have a math test, you can just write zero through nine down one column and do it backwards up the other. Then you have your nine times table answers for you to see.

Or you could write out the whole thing – it’s up to you!

Wouldn’t that have been nice to know ten years ago or twenty? Well, you know it now, so please teach it to your kids!

## II. May I Have a Large Container of Coffee?

Do you have trouble remembering pie to seven digits? Who wouldn’t, right? Instead of memorizing the random assortment of numbers, use this trick.

How many letters are in the word “May”? Three and we all know pi is 3 decimal other digits. So now, how many letters are in the word “I”? Just one.

3.1 – now how many are in the word have? Four, so 3.14 and the word “a”? One, so 3.141 digits.

What about the word “large”? That’s five. The word container? That’s nine. So we have 3.14159 in digits.

Finally, the word “of” and coffee”. Two and six – which gives us pi to seven digits, 3.1415926!

Now you can write down “May I have a large container of coffee” on the top of your tests and you’ll automatically know pie.

Granted, you have to remember the original sentence, but who doesn’t need a large container of coffee when doing math?

It’s also easier to remember things with context, so you may find you can remember the numbers without the words after a while.

Now does anyone at Thinkster Math feel like drinking some coffee?

## III. Little Number Eats the Bigger Number

As a kid, there were lots of people in class who couldn’t figure out the greater-than or lesser-than sign. It was like the two arrows would flip-flop in their heads as soon as they thought they had a grip.

Well not anymore with this math hack. Take that little triangle greater or lesser than sign and draw a circle on top, about halfway in the middle.

Now, give that lesser than sign some teeth. This is your new best friend, the math alligator. Give the eye a pupil and now look at your creation.

With that in mind, here’s all you need to remember. The little number always eats the bigger number. For a while, you may need to draw the alligator so you remember which way his mouth is facing.

But after a month or so it’ll become second nature to imagine the alligator shape on its own.

If you have trouble remember that the little number eats the bigger number and not vice versa stay put. Think about alligators. They’re not exactly skinny, right?

Alligators always want to get bigger – so they’ll eat the bigger thing.

Isn’t it funny how it’s the silliest things that help the most?

## IV. Percentage Hack

Quick, off the top of your head, what’s 40% of 300? You probably don’t know that right?

It’s okay, we didn’t expect you to, not really. Instead of dealing with big numbers like 300, there’s a trick to make them smaller.

Take a zero off the end of the number so that you’re working with smaller numbers. Since it’s a percentage, the math will still work.

So instead of having 40/300 now, you have 4 and 30.

Multiply four and thirty to get your percent. 4 x 30 = 120, which, is what 40% of 300 is.

Just for your sake, let’s do one more example. What’s 20% of 690?

Okay, well that we definitely need a calculator for, right? Wrong. You have 20, which becomes two and 690, which becomes 69.

Now multiply 2 x 69 and you get = 138. If you do the calculation the long way, you’ll get the same thing.

## Math Hacks

While you can’t go into a math test with these math hacks written on a piece of paper, you can memorize them for long enough to write them down when you get your test.

Not that you aren’t allowed to do that, but your teacher won’t know what “may I have a large container of coffee” means written in the margins.

You can share this new knowledge with them if you want or keep it to yourself. We hope these hacks help you in your mathematical life and give you all the answers to the equations.

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