Sum of the first 21 even numbers
The first 21 even numbers range from 2 to 42. On this page, we will show you how to calculate the first 21 positive even whole numbers by using our formula.
The formula to calculate the sum of even numbers is: sum = n × ( n + 1) where n is the even numbers. When we enter 21 into our formula, we get the following:
21 × (21 + 1)
Therefore, the sum of the first 21 even numbers is 462.
Be aware that we consider 2 to be the first positive even number. If you consider 0 to be the first positive even number, then the answer to the sum of the first 21 even numbers would be 420.
Note that the sum of the first 21 even numbers is not the same as the sum of all even numbers up to 21. The sum of all even numbers from 1 to 21 inclusive is 110.
Sum of Even Numbers Calculator
Do you need the answer to a similar question? Get the answer to the sum of the first n even numbers here!
What is the sum of the first 22 even numbers?
Here is the next question in our math book that you may find interesting.