MATHEMATICS 17 



The sign ( ) indicates subtraction, and is called minus; 

 when placed between two quantities, it indicates that the 

 quantity on the right is to be subtracted from that on the 

 left. Thus, in the expression 2517, the sign ( ) shows 

 that 17 is to be subtracted from 25. 



The sign ( X ) indicates multiplication, and is read times, or 

 multiplied by; when placed between two quantities, it indi- 

 cates that the quantity on the left is to be multiplied by that 

 on the right. Thus, in the expression 25 X 17, the sign ( X ) 

 shows that 25 is to be multiplied by 17. 



The sign (*) indicates division, and is read divided by; 

 when placed between two quantities, it indicates that the 

 quantity on the left is to be divided by that on the right. 

 Thus, in the expression 25-7-17, the sign (-*-) shows that 25 is 

 to be divided by 17. 



Division is also indicated by placing a straight line 

 between the two quantities. Thus, 25 | 17, 25/17, and fy all 

 indicate that 25 is to be divided by 17. If both quantities 

 are placed on the same horizontal line, the straight line 

 indicates that the quantity on the left is to be divided by 

 that on the right. When one quantity is below the other, the 

 straight line between indicates that the quantity above the 

 line is to be divided by the one below it. 



The sign (V) indicates that some root of the quantity to 

 the right is to be taken; it is called the radical sign. To 

 indicate what root is to be taken, a small figure, called the 

 index, is placed within the sign, this being always omitted 

 when the square root is to be indicated. Thus V25 indicates 

 that the square root of 25 is to be taken; ^/25 indicates that 

 the cube root of 25 is to be taken; etc. 



NOTE. As the term "quantity" is a very convenient one to use, It 

 will be defined. In mathematics the word quantity is applied to any- 

 thing that is to be subjected to the ordinary operations of addition, 

 subtraction, multiplication, etc., when it is desired not to be more ex- 

 plicit and not to state exactly what the thing is. Thus, the terms "two 

 or more numbers," or "two or more quantities" maybe used. How- 

 ever, the word quantity is more general in its meaning than the word 

 number. 



The signs of aggregation are four in number, viz.: , 



( )? [ ] and { J, respectively called the vinculum, the paren- 

 thesis, the brackets, and the brace. They are used when it is 



