Jeremy buys 3 bags of chips for a party. Stacy and Emily also buy chips for the party. If they need 10 bags of chips total, and Stacy buys 4 bags, how many bags of chips should Emily buy?
Jeremy and Stacy buy 3+4 = <T>add(3, 4)=7 bags of chips.
Since there needs to be 10 total, Emily should buy 10-7=<T>subtract(10, 7)=3 bags of chips.
