Atari 400 User Manual page 164

Now here 's a shortcut. Type in the same addi-
tion problem; only this time, type a question
mark instead of the word PRINT. Press RETURN
and your answer appears.
SCREEN 3
The word PRINT and the question mark can be
used interchangeably as a BASIC command.
They are just two different ways to give the
same instruction to your computer.
Use the HYPHEN key for the minus sign in sub-
traction problems. Type
775-50
and press the RETURN key. It works!
SCREEN 4
162