How to do arithmetic to stings that are converted to numbers?

[sumarri]

So I have the fields that I want to subtract.  One is SequenceNumber_Comment (ex 211) and SequenceNumber_Withdrawal (ex 210). I want to subtract the values and put them in the variable match. Below is the SPLI have but I get an empty value.

| eval match = tonumber(SequenceNumber_Comment) - tonumber(SequenceNumber_Withdrawal)

What do I do??? 

Thank you!!!

[ITWhisperer]

Do your strings have spaces? Try using the trim function

| eval match = tonumber(trim(SequenceNumber_Comment)) - tonumber(trim(SequenceNumber_Withdrawal))

[sumarri]

It does not... I gave it shot, but thank you for the idea!