how do i do this? 1+3+5+7 + ... + 101

Hello,

Number of terms in 1+3+5+7 + ... + 101

nb = (101-1) / 2+1=51

Sum = ((1+101) * 51) / 2=51²=2601

Total numbers from pattern=51

First number+last number is 1+101=102

second number+second last number is 3+99=102.

This means that we can form pairs that make up 102.

Number of pairs=50/2=25

The remaining middle number is 26

Total value of pair=25*102

Total sum of pattern=25*102+26=