The _product counter_ has the out-code 8761. When the product is desired, it is called for, transferred into counter _D_, and the multiplication unit is automatically cleared. It takes time, however, for the machine to perform a multiplication. That is the reason for the preceding coding line and the 6421 in the _C_ field. While the multiplication is going on, we can instruct the machine to do other things that we want done. We can insert or _interpose_ coding lines in between the multiplier line and the product line. For example, if we have a multiplier of 10 digits, we can insert 8 coding lines and maybe more. The 6421 code essentially tells the machine to finish both the multiplication and the interposed instructions, and, as soon as the later one of these two tasks is finished, to transfer out the product to counter _D_. Up to the middle of 1946, the wiring of the machine was a little different and less convenient. When the product was obtained by the multiplication unit, it had to be accepted and transferred at once into one of the 72 storage registers. Dividing Division is called for by first sending the divisor into the _divisor counter_, and this has a code 76 in the _B_ field. If the divisor is in counter 321, the instruction may be: Take the number in 321; enter it as divisor; read the next coding line The coding will then be: 321, 76, 7 Three coding lines later, the dividend is called for, and the coding, if the dividend is in switch 7431, is: 7431, ——, 7 We can send the quotient, when ready, into any desired counter _Q_ by the following two lines of coding: —— —— 642 876 _Q_ —— In the same way as with multiplication, we can insert a number of coding lines in between the dividend line and the first quotient line. Both multiplication and division are carried out in the same unit of the machine, the _multiply-divide unit_. The machine first constructs a table of the multiples of the multiplicand or divisor: 1 times, 2 times, 3 times, ···, 9 times. In multiplication this table is then used by selecting multiples according to the digits of the multiplier one after another. In division the table is used by comparing multiples of the divisor against the dividend and successive remainders, finding which will go and which will not. Since the numbers in the machine are normally of 15 to 23 digits, any particular multiple will be used, on the average, several times, and so this process is relatively efficient. Actually the multiplicand and the divisor go into the same counter. Division, however, has the code 76 and multiplication the code 761, and so the difference is essentially an operation code not in the third or _C_ field. Consulting a Table