The Wang calculator used small keyboard units with nixie-tube displays that were attached to a largish logic box that could be placed on the floor nearby. A third unit, a single punch card reader, provided programmability.
The Model CP-1 Card Reader. source
A punch card would slip into the card reader like bread into a toster. Holes in the card corresponded to key presses on the keyboard. This way a sequence of keys could be programmed for repeated application.
Hand punching was tedious. I wrote an assembler that would run on the CDC 6500 producing a single punched card as output. I don't remember actually solving any actual problems this way other than learning how the machine worked.