You can put this solution on YOUR website! 14ft 3in x 9ft 3in
convert to mm
14ft 3in = (14*12)+3 =171 in
171*25.4 = 4343.4 mm
x 9ft 3in = (9*12)+3 =111 in
111*25.4= 2819.4 mm
Area of garden / area of each slab = number of tiles
Number of slabs = (2819.4*4343.4 )/(450*450)
=2820 slabs