As I head out to trudge behind the snowblower...

You should stay in and waste time at work exercise those braincells. Ready to play?

----------------------

Supply the missing number.

E F G H = 10
F G E E = 13
F H F H = 8
G F G G = 9
= = = =
12 9 11 ??

---------------------

Okie Doke - out into the snow I go. And like always, the answer will be found in the comment later. See you then!