Hidden dots - Sample , Averages,

clg
a=int(rand*1000)
for n = 1 to a
color rand*150,rand*150,rand*150
circle int(rand*300),int(rand*300),2
next n
pause 1
color red
for x = 0 to 9 : for y = 0 to 9
if int(rand*10)<>5 then rect x*30,y*30,30,30
next y : next x
input "How many dots are there?",r$
print a