The 
                  num element represents a set of Arabic or Roman numerals that taken together indicate a single value or represent a single number
                  in a standardized format.
                  
               
               Examples of numbers include: cardinal and ordinal values, weights, measures, currency values, postal codes, telephone numbers,
                  ISBN numbers, scores and results, etc. Where these values include units of measure or other symbols integral to their understanding,
                  the units and symbols must be included as a part of the 
                  num element.
                  
               
               The 
                  
                     role
                      attribute optionally expresses the semantic nature of the number. If omitted, the implicit value 
                  cardinal is assumed.
                  
               
               If the value of the 
                  num element is not in a machine-readable format, the 
                  
                     value (num)
                      attribute optionally allows the inclusion of an alternate representation.
                  
               
               The MathML feature is intended for marking proper mathematical statements within documents and should be used in preference
                  over the 
                  num element whenever equations, formulae or other formal mathematic constructs or operators are being marked.
                  
               
               The 
                  num element must not be used to mark instances of dates and times. Refer to the 
                  
                     time
                      element for more information.
                  
               
               Usage details available in the Usage Details section.
               
             
            Usage Example
At this rate, on the above data, the denudation of the Weald must have 
required <num>306,662,400</num> years;  or say 
<num value="300,000,000">three hundred million</num> years.
    Allowed parents
            address, 
               annoref, 
               annotation (block variant), 
               annotation (phrase variant), 
               m:annotation-xml, 
               aside (block variant), 
               aside (toc variant), 
               block, 
               caption, 
               citation (block variant), 
               citation (phrase variant), 
               d, 
               definition, 
               description (block variant), 
               description (phrase variant), 
               emph, 
               entry (toc variant), 
               entry (index variant), 
               entry (bibliography variant), 
               entry (glossary variant), 
               expansion, 
               xforms:group, 
               h, 
               hd, 
               hpart, 
               item, 
               xforms:label, 
               ln, 
               d:longdesc, 
               meta, 
               note (block variant), 
               note (phrase variant), 
               noteref, 
               object (block variant), 
               object (phrase variant), 
               sel:otherwise, 
               p, 
               ssml:phoneme, 
               ssml:prosody, 
               quote (block variant), 
               quote (phrase variant), 
               its:rb, 
               ref, 
               xforms:repeat, 
               its:rt, 
               s, 
               ssml:say-as (phrase variant), 
               ssml:say-as (text variant), 
               d:simplifiedLanguageDescription, 
               span, 
               spine, 
               ssml:sub, 
               d:summary, 
               td, 
               term, 
               th, 
               d:tour and 
               sel:when
               
            
            Allowed children
            This element may contain text.
            
            This element may contain the following children: ssml:break, 
               char, 
               emph, 
               object, 
               pagebreak, 
               ssml:phoneme, 
               ssml:prosody, 
               its:ruby, 
               ssml:say-as, 
               span, 
               sub, 
               ssml:sub, 
               sup and 
               ssml:token
               
            
            Content model and additional requirements
            
               optional attributes: 
@about, 
                  
@by, 
                  
@class, 
                  
@content, 
                  
@datatype, 
                  
@desc, 
                  
@its:dir, 
                  
@its:translate, 
                  
@property, 
                  
@rel, 
                  
@resource, 
                  
@rev, 
                  
@role, 
                  
@sel:selid, 
                  
@ssml:onlangfailure, 
                  
@typeof, 
                  
@value, 
                  
@xml:base, 
                  
@xml:id, 
                  
@xml:lang and 
                  
@xml:space 
               
               one or more of 
                  
                  a choice of either one of the 14 elements: 
char, 
emph, 
its:ruby, 
object, 
pagebreak, 
span, 
ssml:break, 
ssml:phoneme, 
ssml:prosody, 
ssml:say-as, 
ssml:sub, 
ssml:token, 
sub or 
sup 
                     or text
end of choice 
                  
                
               Note that in addition to restrictions presented in the content model  above, 
                  					use of this element must also respect the following requirement:
                  
                     - The 
                        
num element must neither be empty nor contain only whitespace.
                        
                      
                  
                  Such requirements take precedence over any conflicting statements in the
                     						content model or in the lists above of allowed children and parents.
                  
                
             
            Namespace
            http://www.daisy.org/ns/z3998/authoring/
            Usage Details
            
             Following are examples of how the 
               num element can be used to format identifiers and numbers that are not used in mathemtatical contexts: 
               
            
            
            
               
               - 
                  
                  
Cardinal Numbers
                  
                  
                     
<num role="cardinal" value="30,000">30.000</num> lightyears away.
                
                      
                  
                
               
               - 
                  
                  
Ordinal Numbers
                  
                  
                     
The <num role="ordinal">1st</num> person on the moon was Neil Armstrong.
                
                      
                  
                
               
               - 
                  
                  
Roman Numerals
                  
                  
                     
The motion picture release date is listed as <num role="roman" value="1948">mcmxlviii</num>.
                
                      
                  
                
               
               - 
                  
                  
Phone Numbers
                  
                  
                     
The conference call in line was <num role="phone">+1 416-486-2500</num>
                
                      
                  
                
               
               - 
                  
                  
ISBN numbers
                  
                  
                     
Lib. Binding: <num role="isbn">978-1-1234-4567-1</num>
                
                      
                  
                
               
               - 
                  
                  
Postal Code
                  
                  
                     
There is, in fact, no <num role="postal">90210</num> zip code in the United States.
                
                      
                  
                
               
               - 
                  
                  
Currencies
                  
                  
                     
The US dollar is currently trading at <num role="currency">€0.731768</num> and <num role="currency">$1.02CAD</num>.
                
                      
                  
                
               
               - 
                  
                  
Heights
                  
                  
                     
The tallest man ever was <num role="height">8'11.1"</num> or <num role="height">272 cm</num>.
                
                      
                  
                
               
               - 
                  
                  
Weights
                  
                  
                     
He weighed in at slightly over <num role="weight">220 lbs</num> for the fight.
                
                      
                  
                
               
               - 
                  
                  
Percentages
                  
                  
                     
Only <num role="percentage">15%</num> of people know that statistics are misleading.
                
                      
                  
                
               
               - 
                  
                  
Ratios
                  
                  
                     
The ratio of gas to oil is <num role="ratio">3:2</num> for the lawn mower to work without sputtering.
                
                      
                  
                
               
               - 
                  
                  
Coordinates
                  
                  
                     
The Great Pyramid of Giza is located at <num role="coordinate">29°58′45.03″N</num> <num role="coordinate">31°08′03.69″E</num>.
                
                      
                  
                
               
               - 
                  
                  
Fractions
                  
                  
                     
Add <num role="fraction">1/2</num> cup of milk.
                
                      
                  
                
               
               - 
                  
                  
Mixed
                  
                  
                     
Add <num role="mixed">2 3/4</num> cups of flour.
                
                      
                  
                
               
               - 
                  
                  
Decimal
                  
                  
                     
Pi is often rounded to <num role="decimal">3.14</num> when used in equations.
                
                      
                  
                
               
               - 
                  
                  
Segmented
                  
                  
                     
He made the dubious claim that his Social Insurance Number is <num role="segmented">000 000 001</num>.
                
                      
                  
                
               
            
            
             The 
               span element can further be used to group related sets of numbers: 
               
            
            
            
               
               - 
                  
                  
Ranges
                  
                  
                     
                    It takes between <span role="range"><num>2</num>–<num>5</num></span> cups of flour depending on the size of the loaf.
                
                      
                  
                
               
               - 
                  
                  
Results
                  
                  
                     
                    The final score was <span role="result"><num>3</num>-<num>2</num></span> for Team Canada over Team USA.