Multiply / calculate with 1 form field

Hi all, I think I have a simple question.

I am using Contact Form 7 with Dynamic Text Extension. One of the form fields is just a text field where users can enter a number (for example the number 3). In the e-mail message send to the user I want to use that number and multiply it with 12,5.

It is a kind of ticket ordering system. A user can order 3 tickets. The price for 1 ticket is EUR 12,5. So in the confirmation mail I want the write the total costs: 3 x EUR 12,50 = …..

Can I accomplish this with Dynamic Text Extension?
Thanks in advance!

Tim

https://www.ads-software.com/plugins/contact-form-7-dynamic-text-extension/