Location in a Variable

Here is a program that draws a row of red circles:

' Draw 10 Red Balloons
SCREEN 12     ' start up graphics
COLOR 4       ' set the pen color to red
'
LET BALLOON = 1              ' start with balloon number 1
DO WHILE BALLOON <= 10       ' end with balloon number 10
  
  LET X = 
  CIRCLE (X, 100), 25      ' draw a balloon
  LET BALLOON = BALLOON + 1  ' go on to next balloon
LOOP
'
END

You want each balloon to have a different X for its center, so that there will be a row of balloons. With graphics screen 12 there are 640 pixels across. To evenly space 10 balloons across the screen you want their centers to be spaced about 640 / 10 = 64 pixels apart.