Mark goes into the store to buy some groceries. He buys 6 2$ cans of soup, 2 $5 loaves of bread, 2 3$ boxes of cereal, and 2 $4 gallons of milk. When he gets to the register, he opens his wallet to pay and realizes he only has $10 bills in there. How many $10 bills does he need to use to pay? Let's answer step by step:
Mark buys 6 $2 cans of soup, meaning he spends 6 * 2 = 12 dollars on soup. Mark buys 2 $5 loaves of bread, meaning he spends 2 * 5 = 10 dollars on bread. Mark buys 2 $3 boxes of cereal, meaning he spends 2 * 3 = 6 dollars on cereal. Mark buys 2 $4 gallons of milk, meaning he spends 2 * 4 = 8 dollars on milk. All added together, this means Mark spends 12 + 10 + 6 + 8 = 36 dollars. Since Mark only has $10 bills, he spends 36 / 10 = 3.6 tens on it, which rounds up to 4 as you cannot spend .6 of an undividable item. The answer: 4.