Lower Elementary:
Question: Sandy went to her grandparents’ house for 4th of July. They have 5 dogs, 3 birds, and 7 fish. How many legs do the pets have altogether?
Answer: 26 legs
Solution: A dog has 4 legs, so to find the total number of legs that 5 dogs have, count by 4, five times. 4, 8, 12, 16, 20. Five dogs have 20 legs. A bird has 2 legs, so to find the total number of legs that 3 birds have, count by 2, three times. 2, 4, 6. Three birds have 6 legs. Fish have no legs, so we do not have to count the fish. So, the total amount of legs that the animals have altogether is 26 legs (20 + 6).
Upper Elementary:
Question: Laurie is blending a milkshake to drink while watching fireworks. She mixes half a cup of ice, 1 1/2 cups of vanilla ice cream, 2 pints of milk, and 1 cup of crushed cookies. How much milkshake, in pints, did Laurie make?
Answer: 3 1/2 pints of milkshake
Solution: First, let’s add the cups together. 1/2 + 1 1/2 + 1 = 3 cups. There are 2 cups in 1 pint, so 3 cups = 1 1/2 pints. There are also 2 pints of milk added, so 2 + 1 1/2 = 3 1/2. Laurie made 3 1/2 pints of milkshake.
Middle School:
Question: Charlie earns a 15% commission for each car that he sells. On the week of 4th of July, he was able to sell 5 cars for $15,000 each. How much money in commission did Charlie earn?
Answer: $11,250
Solution: One way to solve this problem is to find out how much money Charlie earns selling one car and then multiply that by the number of cars he sold. He sold one car for $15,000. Percent means for each hundred. There are 150 hundreds in 15,000, so one way to find 15% of 15,000 is to multiply 15 by 150. 150 × 15 = 2,250. Charlie earns $2,250 for one car. If he sold 5 cars then he earned $2,250 × 5 = $11,250.
Algebra and Up:
Question: Michael put his extra fireworks in a safe and locks it with a lock that requires a 4-character password. How many 4-character passwords are possible if the characters are either letters or numbers, the first character has to be a number, the second has to be a letter, and no character can be repeated?
Answer: 291,720 passwords
Solution: There are 10 digits to choose from for the 1st character. There are 26 letters to choose from for the 2nd character. The third character can be either a number or a letter, but there can be no repeated characters. There are a total of 36 characters to choose from, but 2 have been used, so there are 34 characters to choose from for the 3rd character. This means that there are 33 characters to choose from for the 4th character. To find the total number of possible passwords, multiply the possible number of characters in each place together. 10 × 26 × 34 × 33 = 291,720. There are 291,720 different passwords possible.
