What is the sum of the first 100 natural numbers?

×
5000

×
5025

✓
5050

×
5075
What is the sum of the first 100 natural numbers?
5000
5025
5050
5075
The first 100 natural numbers is an arithmetic sequence where the first term a_1=1, 100th term a_{100}=100 and the common difference d=1
Using the sum formula for an arithmetic sequence,
S_n=\dfrac{a_1+a_n}{2}\cdotp d\cdotp n
S_{100}=\dfrac{1+100}{2}\cdotp 1\cdotp 100
=101\times 50
=5050