How can I display calculated numbers?

[furkozoltan]

I want to calculate number from the input field and display the result as a text if I press the button.

For example I type 6 in the input field. I press a button and the result appear as a text (here is the equation 3*input or something like that).

Thank you for your help.

[MrMen]

You want to convert the input text value to a number, multiply it by 3 and convert that to a String: