At the arcade Dave had won 44 tickets. He used some tickets to buy toys. If he still has 41 tickets left How many tickets did Dave use to buy toys?
Dave had 44 tickets. 
He used some tickets to buy toys. 
That means he spent some tickets, and now he has 41 tickets left. 

How many tickets did Dave spend? We don't know. We're told how many tickets he has left, but not how many he spent.