Dragging Formulas

[dawsman]

I am looking to sum two cells on one workbook and then be able to drag the formula down, but the workbook im summing the data from goes across vertically.

So when I drag down I get:
=A1+A20
=A2+A21
=A3+A22

When what I really want is:
=A1+A20
=B1+B20
=C1+C20

Cant figure out how to do this

 

[Jonmo1]

It can be resolved, but will make the formula more cumbersome.
You have to decide if the likeliness of that occurance is worth the extra work to account for it.

If so, do you need to test if EITHER cell is empty, or only if BOTH are empty?

In other words, if only 1 cell is blank, do you still want to do the math (blank + 10 = 10)
Or should the math be done ONLY if BOTH cells contain numeric values ?

 

[Jonmo1]

This will return "" if BOTH cells are empty.
=IF(COUNT(INDEX($1:$1,ROWS($1:1)),INDEX($20:$20,ROWS($1:1)))=0,"",INDEX($1:$1,ROWS($1:1))+INDEX($20:$20,ROWS($1:1)))

This will return "" if EITHER cell is empty
=IF(COUNT(INDEX($1:$1,ROWS($1:1)),INDEX($20:$20,ROWS($1:1)))<2,"",INDEX($1:$1,ROWS($1:1))+INDEX($20:$20,ROWS($1:1)))