Expert: Josh - 7/3/2007

Question
The kitchen floor of your home is 12’6” in width and 10’4” in length.  You have decided to put in a new tile floor.  The tiles that you have selected are 5” on each side.  

1.   Express the area of the kitchen floor, in square feet, as an improper fraction.
2.   Express the area of each tile in square feet.
3.   How many tiles are required to tile the floor?
4.   Explain how your answer relates to the real world


Answer
Hi Bryan,

Since 1 ft = 12 inches, for the second part, 4/12 = 1/3 ft.

12'6" = 12 1/2 ft
10'4" = 10 1/3 ft

1. Area = 10 1/3 * 12 1/2 = (31/3)*(25/2) sq ft.
You can multiply out, simplify the numerator and denominator to obtain an improper fraction. I'll leave this to you.

2. (5/12) * (5/12) = 25/144 sq ft.

3. Divide answer from (1) by 25/144
  This is same as multiplying improper fraction from (1) by 144/25.

4. Length and width may not divide nicely into whole number of files. May end up using more tiles (fragmented ones perhaps) because prior calculation is based on area.

12'6" is same as 12*12+6 = 155 inches
10'4" is same as 12*10+4 = 124 inches.

This second dimension is not divisible by 5 (width of a single tile).