Math CentralQuandaries & Queries


Question from James, a student:

I want to extend my front porshe more to the left atleast 14' 1" length wise and 5' 1" width wise with 4" thickness. Now i already decimalized in feet those inches, resulting with 14.08 length and 5.08width and 0.33 of thickness. I then Get my square feet of 71.53. And go on to cubic feet getting a 23.60 in cubic feet. Now i want to convert to cubic yards so i then divide 23.60 into 27 and get 0.87 . Now my question is how would i use this to go and buy the necessary bags of cement knowing that a 94 lb. bag of cement is 1 cubic foot of bulk material. To fill 4 inch of thickness and 14' of length and 5 of width?

Hi James.

I think you mostly answered your own question. You figured out that this is 23.6 cubic feet and each bag makes 1 cubic foot of cement, so you need about 24 bags. If you order a truck to deliver the cement, they usually work in cubic yards, so you need to order about 0.9 cubic yards.

Stephen La Rocque.

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