Eliae Vineti ... de logistica libri tres

...to the fifth. All the digits of the fourth position make one hundred and four. Since this number is of several signs, it will be marked more safely under the lower line, along with the number born from the digits of the third position: its first sign, 4, in the perpendicular of the fourth position from where it emerged, and the second and third each in their own place in turn. Then that first number 4 will be taken, and it will be added to the unit that shows itself here, reserved from the third position; whence they will become 5, which are to be marked in the sum between the lines in the fourth position. There are now no other digits remaining to be composed; but from the sums of the digits of the third and fourth positions, some remain to be added to the total sum. Among them is first the third sign of the sum of the digits of the third position, which is to be joined to the second sign of the number which was effected from the digits of the fourth position. But since this is nothing, it can add nothing to them; wherefore there will be but one, which, after the five, is to be marked between the lines in the fifth position. There is afterwards the unit, the last sign of the number gathered from the digits of the fourth position, which, placed between the lines in the sixth position of the sum, will have perfected it.

Handwritten note: "With lines inserted, divisions of parts, and in the same"

However, there are those who, whenever so many numbers occur to be joined, think it more convenient to compose them if they distinguish them with inserted lines and consummate them piece by piece. As in the same example: if you draw a line under the four upper numbers and compose only them, you mark their sum, thirty-four thousand one hundred and three, under that line—under which we said the sums of all those composed are to be established. If then you distinguish the four following similarly from the others with a line, which separately...