解15°23‘28’‘×5
=（15°+23′+28″）×5
=75°+115′+140″
=75°+115′+2′+20″
=75°+117′+20″
=76°57′20″
73°35’42‘’÷6
=(73°+35’+42‘’)÷6
=( 72°+95’+42‘’)÷6
=12°+95/6’+7″
=12°+95/6*60″+7″
=12°+950″+7″
=12°+957″
=12°+15′+7″
=12°15′7″