What is the sum of even numbers from 18 to 57? Here we will show you step-by-step how to calculate the sum of even numbers from 18 to 57.
Step 1) We start by finding the first (F) and last (L) even numbers from 18 to 57. It is easy to do that by simply looking at the numbers. The first even number is 18, and the last even number is 56.
F = 18
L = 56
Step 2) Next, we calculate the total even numbers (T) there are from 18 to 57, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (56 - 18 + 2) ÷ 2
T = 40 ÷ 2
T = 20
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of even numbers from 18 to 57, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (20 ÷ 2) × (2 × 18 + (2 × (20 - 1))
Sum = 10 × (36 + 38)
Sum = 10 × 74
Sum = 740
Sum of even numbers from 18 to 57 = 740
Sum of Even Numbers Calculator
Please use the tool below to calculate the sum of even numbers for another set of numbers.