Cumulative Summation

Problem: I have the following list of product “A” monthly sales, and I need to figure out cumulative sales at the end of each month till they reach annual sales figure at the end of the year.

Month	Monthly Sales
Jan	520,514
Feb	361,696
Mar	579,615
Apr	542,257
May	412,810
Jun	359,068
Jul	440,980
Aug	457,383
Sep	511,888
Oct	525,656
Nov	581,972
Dec	452,541

Solution: You need to utilize the SUM function and the $ sign to fix the cell that has the sales figure of the first month. The formula should look like the following:

SUM($C$2:C13)

And the result should look like the following:

Month	Monthly Sales	Cumulative Sales
Jan	520,514	520,514
Feb	361,696	882,210
Mar	579,615	1,461,825
Apr	542,257	2,004,082
May	412,810	2,416,892
Jun	359,068	2,775,960
Jul	440,980	3,216,940
Aug	457,383	3,674,323
Sep	511,888	4,186,211
Oct	525,656	4,711,867
Nov	581,972	5,293,839
Dec	452,541	5,746,380

The $ sign should be added to the first cell only, while the second cell should remain free in order to include more months as you drag the formula downwards.