To find the sum of the series from 1 to 9, we can simply add all the numbers together.
The series is:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9
If we organize the addition in pairs, we can see a pattern:
(1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) + 5
Each pair sums to 10. There are four pairs and one single number left, which is 5.
So, we have:
4 pairs x 10 + 5 = 40 + 5 = 45
Therefore, the sum of the series is 45.
Alternatively, you can use the formula for the sum of the first n natural numbers:
Sum = n(n + 1) / 2
Where n is the last number in the series, which is 9 in this case:
Sum = 9(9 + 1) / 2 = 9 x 10 / 2 = 90 / 2 = 45
Hence, either way, we find that the sum of the series is 45.