1980 -
Elektronika B3-35
Elektronika B3-35 can convert degrees into radians and back, calculate factorials, and supports operations with parentheses. Factorials are calculated number by number, so it takes over five seconds to calculate, for example, the maximum value of 69!.
The scale on the monitor: 1:1




The calculator was intended for engineers and economists, as well as high schools students and secondary school teachers. It was produced by NPO Elektronika (Boguchar) during 1979–1991 and retailed for RUB 105, which dropped to RUB 65 after 1981.

The calculator was later re-branded to Elektronika MK-35. Elektronika B3-35 was also the parent model of Elektronika MK-45, its desktop version.

The calculator could be powered by either three A316 batteries or by a D2-10M line adapter. The continuous operation time was six hours.
Dimensions: 143✕79✕22 mm.
Weight: 0.25 kg.