Deleting columns without messing up formulas

[Questionz]

This simple addition subtraction but I'm stuck...

A basic sample is attached.

1) I have a formula that incorporates the value that is to the left. However, if i need to update the sheet and delete a column, it throws off the whole thing...
I get the #REF error....I thought excel was smart enough to know to that if there's still a value "to the left" to use it....Is there another alternative? or is this a limitation of excel?

2) Also, If I add a column how can I make it have the same formatting as one of the neighboring columns? If I have a lot of rows, it wouldn't be practical to drag and update each formula.

[azumi]

Perhaps somethig like this, pls follow this link

(link removed)

cheers

[JBeaucaire]

I have removed the link above Azumi. Here is your file. Please use the GO ADVANCED > MANAGE ATTACHMENTS to attach files consistently to threads. Thanks.

[samba_ravi]

B5=SUM($A5,SUM($B3:B3),-SUM($B4:B4)) OR
B5=SUM(INDEX($A5:B5,COLUMN()-1),B3,-B4)
Try this and copy towards right
if you insert the column copy the formula from besides cells

[Questionz]

B5=SUM($A5,SUM($B3:B3),-SUM($B4:B4)) OR
B5=SUM(INDEX($A5:B5,COLUMN()-1),B3,-B4)
Try this and copy towards right
if you insert the column copy the formula from besides cells

Thank you so much nflsales! This one worked!!!! I wasn't able to get the indirect azumi mentioned to update. I'm using the first one you mentioned. This is awesome, thank you!

[Questionz]

B5=SUM($A5,SUM($B3:B3),-SUM($B4:B4)) OR
B5=SUM(INDEX($A5:B5,COLUMN()-1),B3,-B4)
Try this and copy towards right
if you insert the column copy the formula from besides cells

My workbook is very large and overloaded with formulas and I'm already having issues with it running slow. which of the two formulas would you recommend to use if I needed each row with that formula repeated 2000 times? So far, I prefer the first one but would summing the whole row be taxing for excel or do you think it should be fine?