BİRİNCİ FEN · BİRİNCİ BÂB · ÜÇÜNCÜ FASIL · Dördüncü Madde
Fourth Article
It explains the easiest way of subtraction.
O Beloved! Know that the mathematicians have said: The easiest way of subtraction is as follows: You write the two numbers to be subtracted, one below the other, just as in addition. And you subtract each digit from its corresponding digit above and write down the remainder beneath the line of operation. If nothing remains, you write zero in that place. If the number being subtracted cannot be taken away from the number below it, you take one ten from the tens place to the left of that digit and add it to it. You subtract what was taken from the minuend and write down the remainder on the line.
If there is no digit in the tens place, you take 1 from the hundreds place, which is equivalent to 10 relative to its presence in the tens place. Then you put the number 9 in that empty tens place and proceed with the operation as previously explained using the remaining 1. You continue this process, performing this operation when necessary, until the subtraction is complete.
270753 – 029872 = 240881
Verification: 5/5
The verification of subtraction is as follows: If possible, it is done by subtracting the verification of the result from the verification of the minuend. If this is not the case, and the verification of the result is greater than or equal to the verification of the minuend, then the number 9 is added to the verification of the minuend, and then it is subtracted from the verification of the result. Then you look at what remains. If this remaining number is equal to the verification of the written result beneath the line of operation, then the calculation is correct. Otherwise, the operation must be repeated.