How do i work out my patio area for how many slabs?

3x3.65=10.95m2-1.68=9.27m2 if you use .4m slabs each covers an area of .16m2 so 9.27/.16=58.9 or round it off to 59 slabs or divide 1m2 by .16=6.25 so you'll need that amount to cover 1m2 and for each 6.25 you'll pay �10.50,59/6.25=9.44x10.50=99.12 or round it off to �100 ok.