2. A small, often pocket-sized, electronic instrument used to perform the basic operations of mathematical calculations.
3. An electronic tool for arithmetic and logarithmic computations which may also include a digital printer and a computer.
4. A calculator in which integrated circuits perform calculations and show the results on a digital display.
Most basic models provide all four arithmetic operations (+, -, x, ÷), usually with a floating decimal.
The massive ENIAC, which weighed 30 tons and filled an entire room, used some 18,000 vacuum tubes, 70,000 resistors, and 10,000 capacitors.
In December, 1945, it solved its first problem regarding the calculations for the hydrogen bomb. After its official unveiling in 1946, it was used to prepare artillery-shell trajectory tables and perform other military and scientific calculations.