Textfield numbers

I just started to try build a mini game (/me is noob:-)
At the end I want to addup 2 textfields, I mean, I have 2 textfields, each have numbers in it, than I tried stuff like,
totaal.text = textField1.text + textField2.text;
I tried give the 2 texfields a variable name, but no matter what i try, the totaal.text dont addup the numbers, but place them after each other.
What do I have to do, to fix this ?
thx :slight_smile: