Elka 22
From Academic Kids
The Elka 22 is the first Bulgarian electronic calculator; it was released in 1965. Weighing 8.5 kilograms (18.7 pounds), the Elka 22 has 3 registers and operates with 12 decimal digits. Addition speed is 0.3 seconds per operation, and division speed is 0.5 seconds. Its power consumption is 35 watts.
This calculator was widely used in Bulgaria and the USSR until 1980. It was produced in Izot factory, which calculators are most known as Elkas.
Image source: Soviet Calculators Collection (http://www.rk86.com/frolov/calcolle.htm)
