To find the sum of the series from 1 to 9, you can simply add all the numbers together. The sequence is:
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
So, let’s sum them up:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9
If we calculate that step by step:
- 1 + 2 = 3
- 3 + 3 = 6
- 6 + 4 = 10
- 10 + 5 = 15
- 15 + 6 = 21
- 21 + 7 = 28
- 28 + 8 = 36
- 36 + 9 = 45
Therefore, the sum of the series from 1 to 9 is 45.
Alternatively, you can also use the formula for the sum of the first n natural numbers, which is:
S = n(n + 1) / 2
Where n is the last number in your series. In this case, n is 9:
S = 9(9 + 1) / 2 = 9 * 10 / 2 = 90 / 2 = 45
This confirms that the sum of the series from 1 to 9 is indeed 45.