What is the sum of odd numbers from 11 to 35? Here we will show you step-by-step how to calculate the sum of odd numbers from 11 to 35.
Step 1) We start by finding the first (F) and last (L) odd numbers from 11 to 35. It is easy to do that by simply looking at the numbers. The first odd number is 11, and the last odd number is 35.
F = 11
L = 35
Step 2) Next, we calculate the total odd numbers (T) there are from 11 to 35, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (35 - 11 + 2) ÷ 2
T = 26 ÷ 2
T = 13
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of odd numbers from 11 to 35, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (13 ÷ 2) × (2 × 11 + (2 × (13 - 1))
Sum = 6.5 × (22 + 24)
Sum = 6.5 × 46
Sum = 299
Sum of odd numbers from 11 to 35 = 299
Sum of Odd Numbers Calculator
Please use the tool below to calculate the sum of odd numbers for another set of numbers.