Maths Tricks

## Interesting and Amazing Facts About Maths

Words such as formula, equation and calculation sounds boring for those who hate Maths as a subject so here are some of the mind boggling facts about maths which are really very interesting. Lets have a look

1. Zero is the only number that can’t be represented in roman numerals.
2. 2 and 5 are the only prime numbers that end with a 2 or a 5.
3. The opposite sides of a dice always add up to seven. From number 0 to 1000.
4. An icosagon is a shape with 20 sides.
5. 40 when written “forty” is the only number with letters in alphabetical order, while “one” is the only one with letters in reverse order.
6. In 1900, all the world’s mathematical knowledge could be written in 80 books; today it would fill more than 1,00,000 books.
7. Zero is the only number known with so many names which include zip, zilch, nil, nought, naught.

1. If you write out pi to two decimal places, backwards it spells “pie”.( 3.14 = PIE.)
2. if you multiply 111,111,111 by 111,111,111, this becomes equal to 12,345,678,987,654,321 it also works for smaller numbers: 111 × 111 = 12321.
3. Abacus is considered the origin of the calculator.
4. Have you heard about a Palindrome Number? It is a number that reads the same backwards and forward, e.g. 12421.
5. The number 9 is believed to be a magical number with certain very interesting properties. This is because if you multiply a number with 9, and add all the digits of the resulting number, the sum would always come out to be 9.
6. Here is an interesting trick to check divisibility of any number by number 3.A number is divisible by three if the sum of its digits is divisible by three (3).
7. What comes after a million, billion and trillion? A quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion and undecillion.
8. Among all shapes with the same area circle has the shortest perimeter.
Maths Tricks

## Square of numbers ending in 5

What People Do ?
Most of the time students multiply both the numbers and find the square and it takes precisely more time than the method i use.

Technique

The Sutra (formula) Ekādhikena Pūrvena means: “By one more than the previous one”.

Now we relate the sutra to the ‘squaring of numbers ending in 5’. Consider the
example 252.

Here the number is 25. We have to find out the square of the number. For the
number 25, the last digit is 5 and the ‘previous’ digit is 2. Hence, ‘one more
than the previous one’, that is, 2+1=3. The Sutra, in this context, gives the
procedure’to multiply the previous digit 2 by one more than itself, that is, by 3′.
It becomes the L.H.S (left hand side) of the result, that is, 2 X 3 = 6. The R.H.S
(right hand side) of the result is522, that is, 25.

Thus 252 = 2 X 3 / 25 = 625.

In the same way,
352 = 3 X (3+1) /25 = 3 X 4/ 25 = 1225;

652 = 6 X 7 / 25 = 4225;

1052 = 10 X 11/25 = 11025;

1352 = 13 X 14/25 = 18225;

Watch The video below to understand the concept clearly

Apply the formula to find the squares of the numbers 15, 45, 85, 125, 175 and verify the answers.

Comment below in case you find any problem in this technique.