Automatically expanding cell ranges

Hi All,

I looked for similar items but I couldn't find any. My apologies if this has been answered before.

The table below has three rows and 7 columns. Row 3 shows cumulative sums of the values in Row 2. Sometimes, Row 2 may not have values (not even a 0). The formula for C3 is =SUM(B2:C2) and =SUM(B2:G2) for G3. The challenge is that I have a very long row and summing it individually would be inefficient.

Is there a way of automating the formula so that the cell ranges expand automatically which I could use to fill to the right?

Thanks.



A B C D E F G
1 Row 1 1 2 3 4 5 6
2 Row 2 1 0 4 15 0 3
3 Row 3 1 1 5 20 20 23