Gripla - 2021, Page 96

GRIPLA94
digit in the next place, [16r] treble the number, which is called a triple, and
multiply it with the figure which you found first, and which we call sub-
triple, and to the right of it multiply it with the triple. And then multiply
it alone with that number which came from the multiplication, which we
call the product. Then take this number as a whole from that upper one
aligned over where the triple stood. Next multiply that same digit in itself
cubically and take that number from that aligned over the digit itself. Take
that digit and triple it here as the former and then find new digit. Multiply
it with both the subtriple and the triple together and always move the older
triple along as you do in smaller root extraction with duple, except here
you shall always skip over one place and add still that same way triple to
triple with correct addition. Continue in such way as long as needed and
you come to the outermost place. And you shall with great care attend to,
when you find the digits, that they not take so much from upper number
that that number has75 no place when you multiply the triple or the other
numbers when you multiply the later digit. Always keep subtriple with
triple. And note that if ciphers come in a subtriple, nothing is a multiple or
triple of them, but they keep to their own places as long as some figure is
to the right of them. And what is least difficult is the addition of a triple,
so that it always goes as written before in the addition art.
All the digits together, those which were subtriples and the outermost
digits too, is the root of the larger number of that which you first wrote
if the subtractions used up the whole number. And you multiply the sub-
triples by themselves cubically and you will find the first number. But if
there is some remainder to the number after subtraction, then that number
is not a cube. But still the remainder, with the subtriples, forms the root
of some cube. And if you multiply the root of the smaller cubically and
add the remainder to that number which comes from the multiplication,
you can get the first number which you wrote. And now we write at the
present no more about this.
These are the digits squared: 3 squared is 9, 2 squared is 4, 4 squared
is 16, 5 squared is 25, 6 squared is 36, 7 squared is 49, 8 squared is 64, 9
squared is 81. And the art to find the digits multiplied is as written before.
These are the digits cubed: 3 cubed is 27, 2 cubed is 8, 4 cubed is 64, 5
cubed is 125, 6 cubed is 216, 7 cubed is 343, 8 cubed is 512, 9 cubed is 729.
75 GKS 1812 has hafin here, but Hauksbók has hafi.