Problems of the week - July 26 to August 1

Rewards for Problems of the week:

5 stars for the correct answer at your level; 10 stars for the next level; 20 stars for 2+ levels up.

 Lower Elementary:

Question: Crayons come in boxes of 12. Each crayon costs 10¢. How much does a box of crayons cost?

Upper Elementary: 

Question: A pack of 3 glue sticks has enough glue in it to cover a square yard—that’s 9 square feet. How many glue sticks would you need to completely cover a banner that is 21 square feet in glue?

Middle School: 

Question: The sticker price of a calculator is $16.00. If you have a 15% off coupon and pay 10% sales tax, how much will the calculator cost you? 

 Algebra and Up:

Question: The formula for the lateral surface area of a cone—that’s the surface that isn’t the base—is π × r × sqrt(h² + r²); h is the height of the cone and r is the radius of its base. A circular #2 pencil is 6 mm in diameter, and a pencil sharpener creates a cone-shaped end that is 20 mm in height. Find the surface area of the sharpened part of the pencil. Find the exact answer, then find an approximate answer.

Challenge problem to take home. 5 stars for the correct answer. 

In this Calcdoku puzzle,

• every row and every column contains every digit 1 through 4 exactly once, and
• every region completes its stated value.