Ed had 6 more marbles than Doug. Doug lost 7 of his marbles at the playground. If Ed had 22 marbles how many marbles does Doug have now?
First, we need to find out how many marbles Doug had in the beginning. If Doug lost 7 marbles, that means he started with 7 more marbles than he has now. So, if we start with the number of marbles Doug has now, and add 7, we'll find out how many marbles Doug had in the beginning. 

We don't know how many marbles Doug has now, but we do know that he had 6 more marbles than Ed, and we know that Ed had 22 marbles. So, if we start with 22 marbles, and subtract 6, we'll find out how many marbles Doug has now. 

22 marbles - 6 marbles = 16 marbles

16 marbles + 7 marbles = 23 marbles

Therefore, Doug had 23 marbles in the beginning.