Click here for the Problem Extension Worksheet version of the Problems of the Week.
Click here for an MS Word version of the Problems of the Week.
Click here for the Canadian Problem Extension Worksheet version of the Problems of the Week.
Click here for a Canadian MS Word version of the Problems of the Week.

Lower Elementary:
Question: Anthony is baking cookies for his friends. He bakes 2 dozen cookies, but 5 of them crumble into pieces. If Anthony needs 18 cookies for his friends, then how many cookies does he have left over for himself?
Answer: 1 cookie
Solution: Since a dozen is 12, Anthony bakes 12 + 12 = 24 cookies. He has 24 – 5 = 19 to give to his friends after 5 of them crumble. Since he needs 18 cookies for his friends, he has 19 – 18 = 1 cookie leftover for himself.

Upper Elementary:
Question: Betsy buys 6 cookies from the store. The cookies have 5, 9, 10, 6, 7, and 11 chocolate chips in them, respectively. What is the average number of chocolate chips per cookie?
(Hint: The average is the sum of all the values in a set, divided by the number of values in the set.)
Answer: 8 chocolate chips
Solution: To find an average, we add up all the values in a set and then divide by the number of values. So, since there are 5 + 9 + 10 + 6 + 7 + 11 = 48 chocolate chips among 6 cookies, that means that the average is 48 ÷ 6 = 8 chocolate chips per cookie.

Middle School:
Question: Chris needs to preheat his oven to 345°F to bake a batch of chocolate chip cookies. The oven has an internal temperature of 70°F when it’s turned off. If it heats at an average rate of 22°F per minute from the moment Chris turns it on to the moment it reaches 345°F, then exactly how long will it take for the oven to reach the correct temperature?
Answer: 12 minutes and 30 seconds
Solution: Since Chris needs the oven to heat up by 345°F – 70°F = 275°F. The average increase in temperature per minute is 22°F, so if we divide the amount the oven needs to heat up by the average increase in temperature per minute, we find that it takes 275°F ÷ 22°F per minute = 12 minutes and 30 seconds for the oven to preheat.

Algebra and Up:
Question: Daria owns a small bakery whose projected total profit can be modeled with the function f(x) = 4,750x + 10,800. If x is a number of months measured from now and the output is a number of dollars, find the projected total profit for 2 years from now.
Answer: $124,800
Solution: There are 24 months in 2 years, so we find the output value of f(x) when x is 24. So, since f(24) = 4,750(24) + 10,800 = 124,800, the bakery is projected to earn a total profit of $124,800 in the next 2 years.