# What is the Sum of First 40 Natural Numbers?

## How to Find Sum of First 40 Natural Numbers?

The below workout with step by step calculation shows how to find what is the sum of natural numbers or positive integers from 1 to 40 by applying arithmetic progression. It's one of an easiest methods to quickly find the sum of any given number series.

step 1 address the formula, input parameters & values.

Input parameters & values:

The number series 1, 2, 3, 4, . . . . , 39, 40.

The first term a = 1

The common difference d = 1

Total number of terms n = 40

step 2 apply the input parameter values in the formula

Sum = n/2 x (a + T_{n})

= 40/2 x (1 + 40)

= 1640/2

1 + 2 + 3 + 4 + . . . . + 39 + 40 = 820

Therefore, **820** is the sum of positive integers upto 40.