( 93 ) 
2 ; and, proceeding to divide the numerator 
by the denominator, by afking how often 2 
in 10 tenths, the anfwer is 5 tenths; which 
5 having 10 for its denominator, I call a 
decimal fraction. So that the way to reduce 
a vulgar fraction to a decimal, I find, is to 
add a cypher to the numerator and divide 
by the denominator. If I had added two 
cyphers and divided by 2, the product would 
have been ,50 that is, 50 parts of 100; 
equal to 5 parts of 103 equal to 4- or i di- 
vided by 2. 
According to this rule, let us reduce 4 to 
a decimal fraction. Adding one cypher to 
the 3 it becomes 30, and dividing 30 by 5 
the anfwer is 6, that is -r%- which being a 
decimal, I write thus ,6. So the vulgar 
fraction 4- reduced to a decimal is ,5, and 4- 
is ,6. This 5 may be fubtracted from the 
6, as in fubtraction of whole numbers, and 
the remainder is ,i; that is, one tenth: for 
as both the 5 and 6 are tenth parts of an 
unit, the remaining i muft necetfarily be - 
of an unit. 
Let us ,now confider the Subtraction of 
Algebraic quantities. This is the Rule. Re- 
verfe the Jigns of the quantity to be fubtratted 
and proceed as in Addition : for example, 
(0 
