No math operation but concaterating

I am working with some variables and setting values, so should be easypeasy. At the end I want to sum up everything. I prompt all variable values - everything ok. But there is no sum but a concaterating instead. So if i have a=2 and b=5 and c=10 (captured as vf.number) when I do {a}+{b}+{c} it is 2510 instead of 17. So what operation to use (I mean I could send them via API and do the math behind with python or php or even as custom code with JS but hey, it should work). Please help.

Hey Adam! Captured inputs automatically store as a String because user inputs can be random. Therefore you would embed the conversion of the variable in your expression into the integer format such as the way below:

Number( {variable_name} )

ie.

Number({a}) + Number({b}) + Number({c})

Let me know if this works for you.