Finding Sum of Consecutive Numbers

Imagine you need to add up a series of consecutive numbers, like 1 + 2 + 3 + 4 + 5. Instead of adding each number one by one, there's a clever formula we can use!

Sum = nfirst number+last number2

where 'n' is the count of numbers in your series.

Why This Works ?

Think of it like pairing numbers: When you have consecutive numbers, the first and last numbers can be paired, the second and second-to-last numbers can be paired and so on... Each pair adds up to the same value!

Example with 1 to 5:

First pair: + =

Second pair: + =

Middle number: (doesn't have a pair)

Total pairs = , plus one middle number

So: (6 × + ) =

Using the Formula:

n =

First number =

Last number =

Sum = 51+52 = 5×62 = 302 =

If you're arranging seats in a theater with 8 consecutive row numbers (like rows 3 to 10): n =

First number =

Last number =

Sum = 83+102 = 8×132 = 1042 =