APF MARK 40
The APF MARK 40 is an arithmetic calculator with 8 digits precision and algebraic logic. It has 5 functions, 18 keys, and an LED (light-emitting diode) display, typical of calculators of this era. The power source is PP3 9V. Note: Montgomery Ward P90
Facts at a glance:
|Power Source||PP3 9V|
If you have an APF MARK 40 that is no longer working, you can first try replacing the PP3 9V battery. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent.
We suggest the following current models as possible replacements: