**ozgurerdogan2**What must I choose for:

(FieldA+FieldB)-10%=

For example

(50+50)-10%=90

I need function for %

*This is a re-post of a comment on Form Calculation - Math Function Reference***Charlie**Hi,

I'm not sure what you would like to do. Are you looking for the function to get the 90% of a value?

For the Form Calculation this is what you need to add to get the 90% of the value. 90% because you are deducting 10%, I presume.

So it should be:

(FieldA + FieldB) * .90 = result

1. Here's how I added mine.

2. In the Form Calculation widget here's my formula.

You can see a sample form here: http://form.jotformpro.com/form/50845074257963.

Do let us know if you need more information on this.

Kind regards.

**ozgurerdogan2**Thank you. I need to deduct by the value that is chosen by checkbox. I think I can do the rest. Thanks.

**Ben**I presume that you are not sure how to get a value from the checkbox, in which case I would recommend checking this guide: How to Assign Calculation Value

Do let us know however if that is not what you have meant.