The total area needing to be covered is 16ft by 12ft or 192 sq.ft.
Each piece of plywood covers 4ft by 8ft or 32 sq.ft.
The number of sheets needed is `192 -: 32=6` .
You need 6 sheets of plywood.
Note that you do not need to cut them. Lay three sheets so that the the widths of the sheets correspond to the width of the room; 3 sheets 4ft. wide cover the 12ft width. Then repeat; the two 8ft. lengths add up to the needed 16ft. Thus you have 2x3=6 sheets without cutting. This is not necessary; the procedure above works all of the time, but it is nice to be able to see the solution.
A= 4ft*8ft=32ft sheet needed each to complte the floor.
To find how many needed, you divide the area of the floor by the area of sheets of plywood available.
Area of floor= 16ft*12ft=192ft
~~ 192ft/32ft= 6 sheets of plywood.