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What is the Sum of First 65 Natural Numbers?

Arithmetic Progression (AP) Calculator

getcalc.com's Arithmetic Progression (AP) calculator, formula & workout to find what is the sum of first 65 natural numbers.
2145 is a sum of number series from 1 to 65 by applying the values of input parameters in the formula.

How to Find Sum of First 65 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 65 by applying arithmetic progression. It's one of an easiest methods to quickly find the sum of any given number series.
step 1 Input parameters and values:
The number series 1, 2, 3, 4, . . . . , 64, 65.
The first term a = 1
The common difference d = 1
Total number of terms n = 65

step 2 apply the input parameter values in the formula
Sum = n/2 x (a + Tn)
= 65/2 x (1 + 65)
= 4290/2
1 + 2 + 3 + 4 + . . . . + 64 + 65 = 2145

Therefore, 2145 is the sum of positive integers upto 65.

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