I would be really surprised if any physical calculator used binary floating point numbers instead of binary-coded decimal. The appearance of repeating bits even for relatively simple decimal numbers like 0.1 is likely to confuse and annoy a calculator user expecting an exact answer.

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OskarS 2 days ago | parent [-]

I would assume most basic calculators use regular floating point circuits, and then just round aggressively for the display.

	▲	inejge 2 days ago \| parent [-]
		Cheap calculators use microcontroller-like CPUs which simply have no room for floating-point hardware. BCD or fixed-point integers in software are much cheaper and simpler.