In our trick set #1, we have learned together to do addition and subtraction mathematical tricks so far. If you haven’t checked them out yet, please go and do it now, before moving on. Now, we will be moving on towards a bit more complex mathematical tricks, which will include useful multiplication and division tricks.
This trick will teach you to multiply any number five times straightforwardly.
Take the number you want to multiply by 5. e.g. 36.
Now cut your number into half, which in our case will be 36/2 = 18.
Just add a zero behind the half number, and you will get the answer which in our example is 180.
Here you’ll have to subtract your odd number by 1. For example, 7 – 1 = 6.
After that half the number you got, which here is 6/2 = 3
Now add 5 at the end of the number you got which becomes 35.
Thus, 35 is the answer in our case.
By learning this trick, you will be easily able to multiply any number by 9 without much hassle.
Let’s take a number, say 8.
We have to multiply it by 9.
For that, just subtract 8 by 1, so we get 7.
Therefore 7 is the first number of your multiplication.
Now, to get the 2nd number, subtract the first number that you got by 9.
It goes as, 9 – 7 = 2.
Combining the first number and second number, we get the answer which is 72.
After learning these tricks, you will no longer need to use hit and trial division method, and you can know in advance if a number is going to get evenly divided by a particular number. Let’s get the tricks started.
If any number has 0 at the end, it can be divided by 10.
If the digits of any number are added up, and the sum can be divided by 9, then the number will also be evenly divisible by 9.
If any number ends with 0 or 5, then it can be divided by 5.
If any number ends in 0,2,4,6,8, then it can be divided by 2.