what is 99+98+97+96 well not just that like adding all numbers less then 100 up that woult take to long to type
100/2 ( 1 + 99) = 5000
My mistake corrected here
Sum of the first 99 integers ===== 99/2 ( 1 + 99) = 4950
**EDITED**
Never mind I was wrong :/
Sum of first n positive integers = n (n + 1) /2
So...sum of 1st 100 positive integers = 100 ( 101) / 2 = 50 * 101 = 5050
Another way to see this
100 + 1 =101
99 + 2 = 101
98 + 3 = 101
.......
We will heve 50 paired sums of 101 each ....so ...50 * 101 = 5050