Stephen signed up to bring 5 gallons of lemonade to the company picnic. He has a 5-gallon bucket that contains 3.5 gallons of lemonade. How many pints of lemonade will he need to add in order to fill the bucket?
He needs 1.5 gallons. There are 4 quarts in a gallon, so he will need 6 quarts. There are 2 pints in a quart, so he needs to add 12 pints.