How to get the sum of fahrenheight and kelvin in my program for loop

Question

So I'm trying to get the total of all the degrees fahrenheit and kelvin values within my for loop, but I don't know how to. Any advice would be great, thank you.

for numbers in range(-10,11,2):

    num_in_decimals=float(numbers)

    fahr_calc=(numbers*9/5)+32

    kelvin_calc=(9/5*numbers+491.67) * 5/9