Nell collects baseball cards. She had 25 cards. She gave 9 cards to John and yet some more to Jeff. Now she has 1 cards left. How many cards did Nell give to Jeff?
Nell has 25 cards. 
She gives 9 cards to John. 
That means she has 16 cards left. 
She gives some more cards to Jeff. 
That means she has 1 card left. 

We can see that Nell gave 7 cards to Jeff.