What is the sum of odd numbers from 42 to 76? Here we will show you step-by-step how to calculate the sum of odd numbers from 42 to 76.
Step 1) We start by finding the first (F) and last (L) odd numbers from 42 to 76. It is easy to do that by simply looking at the numbers. The first odd number is 43, and the last odd number is 75.
F = 43
L = 75
Step 2) Next, we calculate the total odd numbers (T) there are from 42 to 76, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (75 - 43 + 2) ÷ 2
T = 34 ÷ 2
T = 17
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of odd numbers from 42 to 76, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (17 ÷ 2) × (2 × 43 + (2 × (17 - 1))
Sum = 8.5 × (86 + 32)
Sum = 8.5 × 118
Sum = 1003
Sum of odd numbers from 42 to 76 = 1003
Sum of Odd Numbers Calculator
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