Call me crazy, but I think that math is pretty useful. And some people think it’s difficult because most mathematics teachers (for what reason at all) are unsuitable to teach mathematics. Anyway, I’ve noticed that some people have big problems when it comes to percent calculation: 30% of 120? 60% of 50? Ugh…
Where you need this? Everywhere. When there’s a 10% discount in supermarket, you can easily calculate how much money you saved. Just create a decimal point between the last two digits and you get 10%.
10% of 50 is 5.0 or short: 5
10% of 34 is 3.4
10% of 456 is 45.6
10% of 573.2 is 57.32
Got it? Perfect!
In a next step, if you wanna calculate 20%, 30% or 40%, you just follow the rule above with the decimal point and then you multiple the result with the fist digit of the actual percentage (for 20%, you multiply it with 2).
Let me give you an example:
So, 20% of 19 bucks are $3.8 – simple, right?