If a man was born on May 2, 1946, and died on March 3, 2015, how old was he when he died?
This man would have died when he was 68 years old.
2015 - 1946 = 69, but you would subtract one year, because he hadn't reached his 69th birthday yet. (He died in March, but his birthday is in May)
So 69 - 1 = 68 years old.