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: It takes 5 batteries to power 1 flashlight. It takes 4 batteries to power 1 radio. Which of the following requires more batteries: 3 flashlights and 2 radios or 4 flashlights and 1 radio?
Answer: 4 flashlights and 1 radio
Solution: For the first option: 3 flashlights use 5 + 5 + 5 = 15 batteries, and 2 radios use 4 + 4 = 8 batteries. That’s 15 + 8 = 23 batteries in total. For the second option: 4 flashlights use 5 + 5 + 5 + 5 = 20 batteries, and 1 radio uses 4 batteries. That’s 24 batteries in total. Since 24 is more than 23, the second option requires more batteries.

Upper Elementary:
Question: Brandon finds 4 pounds and 8 ounces of wood for a campfire. Emma finds 5 pounds and 11 ounces. Luis finds 9 pounds and 3 ounces. How much campfire do they have in total?
Answer: 19 pounds and 6 ounces
Solution: First, let’s add the ounces: 8 + 11 + 3 = 22 ounces. Since there are 16 ounces in a pound, that’s the same as 1 pound and 6 ounces. Now, if we add the pounds, we get 4 + 5 + 9 = 18 pounds, plus 1 pound and 6 ounces makes 19 pounds and 6 ounces.

Middle School:
Question: An unroasted marshmallow has a volume of 0.25π cubic inches. After Andrew roasts the marshmallow over a campfire, its volume is 150% its original volume. What is the post-roast volume of the marshmallow?
Answer: 0.375π cubic inches
Solution: To find 150% of 0.25π, we can multiply the 1.5 by 0.25 and then by π: 1.5 multiplied by 0.25 is 0.375, and 0.375 multiplied by π is 0.375π. So, the volume of the roasted marshmallow is 0.375π cubic inches.

Algebra and Up:
Question: A triangular prism-shaped tent has a rectangular base that is 6 feet wide and 8 feet long. The isosceles triangular sides have bases that are 6 feet wide and edges that are 5 feet in length. If all the walls of the tent are pulled perfectly flat, then what is the volume of the tent?
Answer: 96 cubic feet
Solution: We’re missing the height of the tent. To find it, we can take a right triangular half of an isosceles triangular side of the tent. One leg is half of 6 feet, so 3 feet, and the hypotenuse is 5 feet, so the other leg—the height of the tent—is 4 feet. So, the area of that face of the tent is 0.5 × 6 × 4 = 12 square feet. The length of the tent is 8 feet, so its total volume is 12 × 8 = 96 cubic feet.