| Rule | Description |
|---|---|
| 1 |
If the sum of digits of two digit number is ‘a’ and if the digits or the number are reversed, such that number reduces by ‘b’, then, Original Number \[=\frac{11a+b}{2}\] |
| 2 |
If the sum of digits of two digit number is ‘a’ and if the digits of the number are reversed, such that number increases by ‘b’, then, Original Number \[=\frac{11a-b}{2}\] |
| 3 |
If the difference between a number and formed by number reversing digit is x, then the difference between both the digits of the number is \[\frac{x}{9}\] |
| 4 |
If the sum of a number and the number formed by reversing the digits is x, then the sum of digits of the number is \[\frac{x}{11}\] |
| 5 |
Remainder Calculation: If \[\frac{a^n}{a-1}\], then remainder will always be 1,whether n is even or odd. |
| 6 |
Remainder Calculation: If \[\frac{a^{\left(even\ number\right)}}{a+1}\], then remainder will be 1. |
| 7 |
Remainder Calculation: If \[\frac{a^{\left(odd \ number\right)}}{a+1}\], then remainder will be a. |
| 8 |
If n is a single digit number, then in \[n^3,n\] will be at unit place. It is valid for the number \[0, 1, 4, 5, 6 \ or \ 9\]. |
| 9 | If n is a single digit number then in \[n^p\], where p is any number (+ve), n will be at unit place. It is valid for 5 and 6. |