BİRİNCİ FEN · BİRİNCİ BÂB · ÜÇÜNCÜ FASIL · Beşinci Madde
Article Five
Regarding the easiest method for doubling (taz’if).
O, beloved! Know that the mathematicians have said: In truth,
doubling is the summation of two numbers of the same kind. However, it is not necessary to repeat the identical number. Rather, you add each digit as if there were a multiple beneath it. The process proceeds in this manner:
320573
641146 Verification 4/4
The verification of this doubling operation is as follows: You double the verification of the given number and subtract it from the result’s verification. If they are equal, then the doubling operation is correct. Otherwise, the operation is erroneous.