Some Mathematics Tricks We Got from our School

Our school had excellent mathematics faculty.They taught us many tricks which are not taught elsewhere.
There are lots of shortcut tricks to perform many mathematical calculations .Many of them are not applicable in our daily life.If we see all of them together we will have a slothful attitude to ignore it altogether. Here i have filtered out just Important 6 Tricks which would be very much useful for us in our daily life!

So just have a little patience to go through these 6 awesome tricks.

It wont take you more than 30 minutes to master all the 6 of these tricks.

Trick 1

A quick way to square numbers that end in 5

• 75² = 5625

  75² means 75 x 75.
  The answer is in two parts: 56 and 25.
  The last part is always 25.
  The first part is the first number, 7, multiplied by the number "one more", which is 8:
  so 7 x 8 = 56
  

• Similarly 85² = 7225 because 8 x 9 = 72.

Trick 2

You do not need to the multiplication tables beyond 5 X 5

• Suppose you need 8 x 7

8 is 2 below 10 and 7 is 3 below 10.
Think of it like this:

The answer is 56.

The diagram below shows how you get it.

You subtract crosswise 8-3 or 7 - 2 to get 5,
the first figure of the answer.

And you multiply vertically: 2 x 3 to get 6,
the last figure of the answer.

Trick 3

An elegant way of multiplying numbers using a simple pattern.

• 21 x 23 = 483

This is normally called long multiplication but
actually the answer can be written straight down.

We first put, or imagine, 23 below 21:



There are 3 steps:

a) Multiply vertically on the left: 2 x 2 = 4.
This gives the first figure of the answer.


b) Multiply crosswise and add: 2 x 3 + 1 x 2 = 8
This gives the middle figure.


c) Multiply vertically on the right: 1 x 3 = 3
This gives the last figure of the answer.

And thats all there is to it.

• Similarly 61 x 31 = 1891
  



• 6 x 3 = 18; 6 x 1 + 1 x 3 = 9; 1 x 1 = 1

Trick 4

Multiplying a number by 11.

To multiply any 2-figure number by 11 we just put
the total of the two figures between the 2 figures.

• 26 x 11 = 286

  Notice that the outer figures in 286 are the 26
  being multiplied.

  And the middle figure is just 2 and 6 added up.

• So 72 x 11 = 792

Trick 5

Method for diving by 9.

• 23 / 9 = 2 remainder 5

  The first figure of 23 is 2, and this is the answer.
  The remainder is just 2 and 3 added up!

• 43 / 9 = 4 remainder 7

  The first figure 4 is the answer
  and 4 + 3 = 7 is the remainder - could it be easier?

Trick 6

Use the formula ALL FROM 9 AND THE LAST FROM 10 to perform instant subtractions.

For example 1000 - 357 = 643

We simply take each figure in 357 from 9 and the last figure from 10.

So the answer is 1000 - 357 = 643

And thats all there is to it!