Barry and his wife Mary have accumulated over $3.5 million during their 50 years of marriage. They have three children and five grandchildren.

Barry and his wife Mary have accumulated over $3.5 million during their 50 years of marriage. They have three children and five grandchildren. 

How much money can they gift to their children in 2014 without any gift tax liability?

I am having trouble with the right formula to use. I keep missing one part I think but how to format it is what I'm missing on.