## How do you calculate 1+2+3+4+5+6+7+8+9+10 quickly?

### Solution:

The generalized formula to find the sum of first N natural numbers is

(N * (N + 1) ) /2

For the series given, the value of N is 10

So substituting value of N in the generalized formula

( 10 * (10 + 1) ) / 2

=> (10 * 11 ) / 2

=> 110/2

**=> 55**

**Hence the answer is 55**