You can put IF BUTTON(0)==1 THEN PRINT "UP" into your program, but it won't trigger when you press multiple buttons. Because the number is binary, you can write IF BUTTON(0) AND 1 THEN PRINT "UP" and it will trigger even when you're pressing multiple buttons. The number inside the parentheses is 0-pressed 1-moment pressed with repeat 2-moment pressed without repeat 3-moment released