My age is five times that of my son. Next year, my son will be eight years old. How old am I now?
If the son is going to be eight years old after a year from now, then currently, he is 8-1 = 
<gadget id="calculator">8-1</gadget>
<output>7</output>
7.
Since the father's age is five times that of the son, currently he is 5*7 = 
<gadget id="calculator">5*7</gadget>
<output>35</output>
35 years old.

<result>35</result>