Answer :
[tex]1+2+3+4+\ldots+99+100=\\
(1+100)+(2+99)+(3+98)+\ldots(50+51)=\\
50\cdot101=\\
5050[/tex]
You can use Gauss method...
Sum from 1 to n = [n(n+1)] / 2
So... 1 to 100 = [100(100+1)] / 2
= [100(101)] / 2
= [10100] / 2
= 5050
Sum from 1 to n = [n(n+1)] / 2
So... 1 to 100 = [100(100+1)] / 2
= [100(101)] / 2
= [10100] / 2
= 5050
