An auditorium is to seat 2,400 people. the building code requires three square feet for each person. how many square meters will that auditorium have?

Explanation:

Method 1)

2,400 person (3 ft² / person) = __?__ m² .

The units of "person" ; 'cancel out"; since "person/ person" = 1 ; and 1/1  = 1. 

and we have:  "2,400 * (3 ft²) = 7, 200 ft² .

We are ask to find the value, in units of "m² " ;

     → So; we convert "7, 200 ft² " ;  to "m² " ;

    → Note the conversion:  1 m² = 10.7639 ft² ;

    → 7, 200 ft² * [ ( 1m²) / ( 10.7639 ft²) ] ;

                          = [ (7, 200 ) / (10.7639 )] m² ;
 
                          =  668.9025353264151469 m² ;
       
                            ⇒    Round to 668.903 m² .

Method 2) 


   2,400 person (3 ft² / person) = __?__ m² .

Since we want the answer is units of:  "m² "  ;
 
Let us convert:  "3 ft² " to units of:  "m² " ;  and then rewrite the problem.

  → Note the conversion:  1 m² = 10.7639 ft²  ;

                           = [ (7, 200 ) / (10.7639 )] m²
 
                          =  668.9025353264151469 m²

                                ⇒    Round to 668.903 m² .

Method 3) 

    2,400 person (3 ft² / person) = __?__ m² . 

  → Note the conversion:  1 m² = 10.7639 ft²  ;

    (2,400 person) * (3 ft² / person) * [ ( 1m²) / ( 10.7639 ft²) ] ;

             =  { [ (2,400) * (3) * (1) ] / [ 10.7639 ] }  m² ;

             = { [ (2,400) * (3) ] / [ 10.7639 ] }  m² ;   {Note:  The "1" can be ignored.}.

             =  [ (7,200) / (10.7639) ]  m² ;
 
             =  668.9025353264151469 m² ;

                      ⇒ Round to 668.903 m² .