What is the sum of odd numbers from 20 to 185? Here we will show you step-by-step how to calculate the sum of odd numbers from 20 to 185.
Step 1) We start by finding the first (F) and last (L) odd numbers from 20 to 185. It is easy to do that by simply looking at the numbers. The first odd number is 21, and the last odd number is 185.
F = 21
L = 185
Step 2) Next, we calculate the total odd numbers (T) there are from 20 to 185, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (185 - 21 + 2) ÷ 2
T = 166 ÷ 2
T = 83
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of odd numbers from 20 to 185, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (83 ÷ 2) × (2 × 21 + (2 × (83 - 1))
Sum = 41.5 × (42 + 164)
Sum = 41.5 × 206
Sum = 8549
Sum of odd numbers from 20 to 185 = 8549
Sum of Odd Numbers Calculator
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