Complete Program

Here is the completed program. You may wish to run it a few times and see how good your crowd estimating ability is.

'
LET NUMBER = INT( 30000*RND )    ' pick a random number 0 to 29,999
'
SCREEN 12
FOR DOT = 1 to  NUMBER 
  LET X = INT( 640*RND )    ' pick a random column 0 to 639
  LET Y = INT( 480*RND )    ' pick a random row    0 to 479 
  PSET( X, Y)               ' draw the random point
NEXT DOT
'
PRINT "How many spots are there"
READ  GUESS
'
LET ERROR = NUMBER - GUESS
PRINT "There are", NUMBER, "spots.  You missed by", ERROR, "spots."
'
END

There are many other graphics progams you could write that use random numbers and FOR loops. For example, your program could draw circles or squares placed at random locations. Or the program could randomly change the color of the graphics pen before drawing each figure.

Remember that there are 16 colors for graphics screen 12, numbered from 0 to 15. You can change the pen color (the color the system uses to draw with) by using one of these integers with the COLOR statement:

COLOR ColorNumber