I AM POURING CEMENT

8FT. X 8 FT. X 4 INCHES

8FT. X 8FT. X 5 INCHES.

8FT. X 8FT. X 5 1/2 INCHES.

WHAT IS THE FORMULA?

THANKS,
DAVID
6TH GRADE
STUDENT

Hi David,

When you calculate a volume of concrete the usual units are cubic yards, or sometimes people just say yards. The volume of a rectangular slab as you have is given by

volume = length width thickness

Since you want the volume in cubic yards you need to express the dimensions in yards.

there are 3 feet in a yard so

8 ft = ⁸/₃ yards

There are 36 inches in a yard so

4 inches = ⁴/₃₆ yards

Thus the volume of your first example is

 ⁸/₃  ⁸/₃  ⁴/₃₆ = 0.79 cubic yards

Penny