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Sometimes you need to quickly find out if you can share something evenly between 2, 3, 4, 5, 6, 7, 8, 9, or 10 people. Then, do not do long division! Just follow these simple divisibility rules. For example, a number is divisible by 3 if the sum of the digits of the number is divisible…

412 Subtract 1 from 41 to get 40. Then add 1 and twice 40 to the square of 40. 402 + 40 + 40 + 1 = 1600 + 80 + 1 = 1681 Example #11 Find 612 61 = 602 + 60 + 60 + 1 = 3600 + 120 + 1 = 3721

Suppose you are subtracting 28 from 65. Doing vertical subtraction is fine. However, if you are pressed for time and you need to get an answer quick, this is not the time to set up vertical subtraction and then do borrowing and regrouping. Here is the trick: Subtract 30 from 65 to get 35 and…

If you multiply an even number less than 10 by 6, here is how the answer will look like. The number in the ones place will be the even number you multiply 6 by. The number in the tens place will be half the even number. Example #8 6 × 8 = 48  6 × 6 =…

Now, we show you a math trick that you can use to square a number easily and fast. Take a close look at the figure below! It shows how you can use a cool math trick to square a two-digit number much faster than the traditional way of doing it.  The goal is to rewrite one…

To multiply a number by 10, just add one zero next to the number. To multiply a number by 100, just add two zeros next to the number. To multiply a number by 1000, just add three zeros next to the number. Example #5 65 × 10 = 650 Example #6 14778 × 1000 = 14778000

Most of us learn to add on paper from right to left. And it is fine when doing math with paper and pencil. However, if you want to add 2-digit numbers fast in your head, it is better to add from left to right. Example #3    56+ 23 A quick way to add 56 and…

Even if you know your multiplication table, this trick may come in handy if you are having a brain freeze all of a sudden. First, put your left hand and your right hand up and starting with your left little finger number your fingers as shown below. Example #1 To do 9 × 5, fold…