For example if my calc divides 1 by 0

Result: IIf([SecondNumber]=0,0,[FirstNumber]/[SecondNumber])

IIF Function

IIf([Qty]= 0,0,[Answer1]/Qty]) This is what my calc looks like. I am getting the following error on this.

THE EXPRESSION YOU ENTERED HAS AN INVALID NUMBER.

Looks like it is finding a problem with the 0 numbers.

You are missing a square bracket on the second Qty
IIf([Qty]= 0,0,[Answer1]/Qty]) should be
IIf([Qty]= 0,0,[Answer1]/[Qty])

Sorry. I have corrected that but still get the same message.
IIf ( [Qty]= 0 ,0 , [Answer1] / [Qty] )

Where are you using the function?
Is it in a Query?
Can you post some screenshots please?

What data types are Qty and Answer1?

The data type of Qty is number and Answer1 are a expression

If you are using & in a field name it is probably being miss interpreted by Access.
If the Width and Bleed are being added together you should be using a +

The general rule for field names is only use letters and numbers.  I know that you can use some other characters like the underscore  _  but it could be mistaken too easily.

Thank you Scott. I will change it. It still does not fix the problem.

So which was it?  Poor field name or adding the fields together?
What is your new equation?  

Remember your Order of Operation (PEMDAS).

The original problem is still not solved. I am still getting a #Div/0! error.

Try writing it like this:

   IIF([Answer2] <> 0, [Qty]/[Answer2], 0)

I have tried the argument on the TechHelp template. I used the QuoteDetailQ and i am getting the same problem. I am using Office 365.

What is Answer2?  Maybe I missed it, but I see Answer1 is a calculation, is Answer2? Your problem might be happening before you even get to the point of trying to do a calculation with Answer2.

Ah I see the query now, it is a calculation. I cant see the calculation but I can see Answer1, try making it like this in your answer 2

Answer1: IIF([Width&Bleed]=0,0,Int([PrintableWidth]/[Width&Bleed]))

Then move onto OptionB

Can we see the Table design for DigitalCalcT?

Also try hardcoding each of the values, only swapping out one at a time, to see if any work, then it might narrow down which Field is causing the problem.

The problem is probably caused by the fact that Access needs to evaluate the first values before it can perform the second set of calculations. Calculate the value of Answer1 and Answer2 in the query. Then make ANOTHER query based on that one. In the 2nd query your IIF function should work.