New Invention In Algebra
By Albert Girard, mathematician
for the solution of equations,
for recognizing the number of solutions they receive,
with several things which are necessary for the perfection of this divine science.
Amsterdam 1629


Mathematical Complement,
The Beginnings of Arithmetic
Pronunciation Of Numbers
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The Four Operations
Addition, Subtraction, Multiplication, Division.
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Addition
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Subtraction
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Multiplication
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Division
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1 Preparation for fractions
Prime numbers are those which have no other divisor than themselves and unity.
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2 Preparation for fractional numbers
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Operations on fractions
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on the
Rule Of Three
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On The Characters Of Powers And Roots
Although the marks (2), (3), (4) denote the second, third, forth powers,
that is squares, cubes, square-squares,
which have been made to serve only as integers,
yet when they are fractions,
the numerator is the power and the denominator is the root.

For example, in (3/2)49, the 3 signifies the cubic power, and 2 the square root,
which can be pronounced as "third power of the second root of 49",
or "the cube of the root of 49" or "the square root of the cube of 49",
for it is always 343.

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