Why isn't this 0? What is it

[Vijay_chen]

Why isn’t this 0? What is it. Look at the picture for details

[Dominik_Bosnjak]

Looks like either a typing or formatting issue. Rollup fields return arrays by default, though that DHL field might also be returning a string.

Have you tried clicking the Formatting tab in the formula editor and setting the output to an integer?

Failing that, can you share the rollup formulas you’re subtracting? Wrapping both formulas in VALUE() calls can probably serve as a band-aid fix for this specific brand of type errors, but you should really look to fix the underlying mechanism. Trying to correct faulty formulas with more formulas is a recipe for developing bad habits and even worse-performing apps.

[Vijay_chen]

I have set the format, I also suspected that there is a very small decimal hidden here, but I save 8 decimal places, still can not find the problem. And all the other records that subtracted to zero were normal, just these two anomalies

[kuovonne · Accepted solution]

It’s a known floating point issue. You can only see a set number of decimal places, but under the hood, Airtable is calculating more decimal places.

If you want it to be exactly zero, (without the minus), ROUND() the numbers. Note that you will still see however many decimal places you specify in the formatting options.

[Bill_French]

kuovonne:

known floating point issue

Yep, and it’s a long-standing issue in Airtable but we cannot blame Airtable; this is a common problem in many languages actually.

Floating Point Error - Addition/Subtraction Formulas

There is a floating point bug that I can only get to rear its head in a particular way. I have distilled down to this simple example. Add three particular numbers (haven’t played around with which numbers cause the problem, but these do), subtract the sum from the same number in another field and the result is displayed as zero, as it should. Put an IF statement in another field comparing the result to zero, and the comparison fails. I was able to get the IF statement to display the floating poi…