# 11 Simple Math Hacks

If you have issues with math, it's not your fault. The problem is that nobody taught you the most useful math tricks in school.

**Birght Side **put together the best tricks that will help you count easily and quickly. With these, any kind of calculation will be easy as pie.

### The easy percent of a number

### Quick square calculation

This trick will help you find the square root of a two-digit number that ends with a five. Multiply the first digit by itself and add 1 to it. Then write 25. That's it!

### Multiplication by 9 made easy

### Quick multiplication by 5

Divide a given number by 2. If the result is a whole number, add 0 at the end. If the result is not a whole number, ignore the decimal and just add 5 at the end.

### Easy multiplication by 11

### Simple multiplication by 4

The trick here is to multiply your number by 2, and then multiply it by 2 again.

### A simply way to calculate tips

If you need to leave 15% of your order as tips, there is a simple way to find how much you need to give. First, find 10% of your sum (divide your sum by 10), and then add another half of the result. That's your tip.

### Difficult multiplication made easy

If you need to multiply large numbers while one of them is even, you can simply regroup them to get an answer.

### Division by 5

Dividing large numbers by five is, in fact, pretty simple. All you need to do is multiply your number by 2 and then move the decimal point.

### Subtracting from 1,000

There's a simple rule for subtraction from 1,000: just subtract all the digits from 9, and the last digit from 10.