Casio CM-605

The Casio Mini CM-605 calculator was a very simple four function calculator with a large flourescent six digit display. An unusual feature was that the six digit display could be doubled up to show a further six digits for certain calculations (this feature did not work for division). Since there was no scientific notation, this was needed to compute the product of two relatively large numbers. Like most Casio calculators of the era, it had a horizontal layout. The zero only used the bottom four segments of the display, presumably to distinguish it from the digit eight.