Eliae Vineti ... de logistica libri tres

...you will place beneath them. Thus, under the line, you will have fifty-nine marked as the days, which is the sum of the days attributed to those months.

However, if you find many circles in any place by themselves, a single one marked under the line in that same position will suffice for those many. And if those same circles appear in any position with significant signs, they are nothing; they add nothing to the significant signs. As here, the first and second positions of those to be composed are occupied by sets of three circles, for which you will mark single ones beneath.

Grapheme

In the third position are 3 and 5 with 0; these make only 8, which you will mark below. In the fourth are two circles and 6, which make no more than six, to be marked under the line. Finally, in the last position, 1, 2, 4 make seven, which you will mark 7 below the line. Therefore, these three numbers—ten thousand and three hundred, twenty-six thousand, and forty thousand and five hundred—when composed, create this sum: seventy-six thousand and eight hundred.

But if from the joined digits of one position a number greater than a single digit grows, for the designation of which two or more signs are necessary, you will place the first of those signs in the same position underneath; and you will reserve the rest for the following positions. As in nine hundred and ninety with seven...