Question 176606
Convert all of the measurements to inches.
12'8"=12x12+8=144+8=152 inches
19'9"=18x12+9=216+9=225 inches
The total kitchen area is the product of the width and length
{{{A[k]=152*225=34200}}}
Each tile has an area of 
{{{A[t]=8*8=64}}}
The total number of tiles would be the kitchen area divided by tile area.
{{{N=A[k]/A[t]=34200/64=534.375}}}
You would round up to 535 tiles. 
Practically, you would typically get 10% more for mismeasurement, cutting mistakes, and future replacement.