What is the sum of odd numbers from 1 to 4001? Here we will show you step-by-step how to calculate the sum of odd numbers from 1 to 4001.
Step 1) We start by finding the first (F) and last (L) odd numbers from 1 to 4001. It is easy to do that by simply looking at the numbers. The first odd number is 1, and the last odd number is 4001.
F = 1
L = 4001
Step 2) Next, we calculate the total odd numbers (T) there are from 1 to 4001, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (4001 - 1 + 2) ÷ 2
T = 4002 ÷ 2
T = 2001
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of odd numbers from 1 to 4001, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (2001 ÷ 2) × (2 × 1 + (2 × (2001 - 1))
Sum = 1000.5 × (2 + 4000)
Sum = 1000.5 × 4002
Sum = 4004001
Sum of odd numbers from 1 to 4001 = 4004001
Sum of Odd Numbers Calculator
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