How to use adding and calculating machines : full-keyboard adding machine, ten-key adding machine, printing calculator, rotary calculator, key-driven calculator /
Walker, Arthur L. 1899-
How to use adding and calculating machines : full-keyboard adding machine, ten-key adding machine, printing calculator, rotary calculator, key-driven calculator / Arthur L. Walker, J. Kenneth Roach [and] J. Marshall Hanna. - 3rd ed. - New York : Gregg Division, McGraw-Hill, [1967] - 250 p. : ill.
070678235
Calculators--Problems, exercises.
How to use adding and calculating machines : full-keyboard adding machine, ten-key adding machine, printing calculator, rotary calculator, key-driven calculator / Arthur L. Walker, J. Kenneth Roach [and] J. Marshall Hanna. - 3rd ed. - New York : Gregg Division, McGraw-Hill, [1967] - 250 p. : ill.
070678235
Calculators--Problems, exercises.