Floating point numbers

 
$a

 
=

 
1.234

 
;

 
$a

 
=

 
1.2e3

 
;

 
$a

 
=

 
7E-10

 
;



The size of a float is platform-dependent, although a maximum of ~1.8e308 with a precision of roughly 14 decimal digits is a common value (that's 64 bit IEEE format).