[tex]1\quad foot\quad :\quad \frac { 1 }{ 4 } \quad inch\\ \\ 4\quad \cdot \quad 1\quad foot\quad :\quad \frac { 1 }{ 4 } \quad inch\quad \cdot \quad 4\\ \\ 4\quad feet\quad :\quad 1\quad inch[/tex]
This means that:
[tex]4\quad feet\quad :\quad 1\quad inch\\ \\ \frac { 27 }{ 2 } \cdot \quad 4\quad feet\quad :\quad \frac { 27 }{ 2 } \cdot \quad 1\quad inch\\ \\ \frac { 108 }{ 2 } \quad feet\quad :\quad \frac { 27 }{ 2 } \quad inches\\ \\ 54\quad feet\quad :\quad \frac { 27 }{ 2 } \quad inches\\ \\ [/tex]
13 + 1/2 inches is the same as 54 feet
