python django website. take user input run through a math equation return to user response

I want to take user input from a website and then run it through a function and then return the answer. Im working on django.

How can i do that for exsample

 myvar1 = htmlwebinput1
 myvar2 = htmlwebimput2

total = myvar1 + 5 * myvar2

print "<ptaghere> this is your answer :</ptaghere>" + str(total)