What is the sum of even numbers from 7 to 42? Here we will show you step-by-step how to calculate the sum of even numbers from 7 to 42.
Step 1) We start by finding the first (F) and last (L) even numbers from 7 to 42. It is easy to do that by simply looking at the numbers. The first even number is 8, and the last even number is 42.
F = 8
L = 42
Step 2) Next, we calculate the total even numbers (T) there are from 7 to 42, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (42 - 8 + 2) ÷ 2
T = 36 ÷ 2
T = 18
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of even numbers from 7 to 42, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (18 ÷ 2) × (2 × 8 + (2 × (18 - 1))
Sum = 9 × (16 + 34)
Sum = 9 × 50
Sum = 450
Sum of even numbers from 7 to 42 = 450
Sum of Even Numbers Calculator
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