What is the sum of odd numbers from 4 to 45? Here we will show you step-by-step how to calculate the sum of odd numbers from 4 to 45.
Step 1) We start by finding the first (F) and last (L) odd numbers from 4 to 45. It is easy to do that by simply looking at the numbers. The first odd number is 5, and the last odd number is 45.
F = 5
L = 45
Step 2) Next, we calculate the total odd numbers (T) there are from 4 to 45, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (45 - 5 + 2) ÷ 2
T = 42 ÷ 2
T = 21
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of odd numbers from 4 to 45, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (21 ÷ 2) × (2 × 5 + (2 × (21 - 1))
Sum = 10.5 × (10 + 40)
Sum = 10.5 × 50
Sum = 525
Sum of odd numbers from 4 to 45 = 525
Sum of Odd Numbers Calculator
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