Multiplying
When we wish to multiply one number by another and get a product, we have 3 numbers. We tell the machine about each of these numbers on a separate line of coding. Multiplication is signaled by sending a number into the multiplicand counter. The multiplicand counter has an in-code 761. If the multiplicand is in 321, the instruction is:
- Take the number in 321;
- enter it as multiplicand;
- read the next coding line
The coding is:
321, 761, 7
On the third following coding line, the multiplier is sent into the multiplier counter. If the multiplier is in switch 741, the instruction is:
- Take the number in 741;
- enter it as multiplier;
- read the next coding line
The coding is:
741, ——, 7
We do not punch anything in the middle field: the machine is “educated” and “knows” that it has started a multiplication and needs a multiplier, and it expects this multiplier in the third coding line. To have no code for the multiplier counter is, of course, a departure from the general rule, but it saves some punching and permits the use of this space for certain other codes, thus saving some operating time.