You measure a distance of 185 feet. how many meters is this?
there are 12 inches in 1 foot.
there are 2.54 cm in 1 inch.
there are 100 cm in 1 m.
( show work i need to know how to do this.) i need a good example.

-- Take the 185 feet.

-- Multiply it by (12 inches / 1 feet)

-- Multiply it by (2.54 cm / 1 inch)

-- Multiply it by (1 meter / 100 cm)

Doesn't all this multiplying change the value of the 185 feet ?

NO, it doesn't.  Each of those fractions has the exact same thing on top and on the bottom.  So each of those fractions is equal to ' 1 '.  It doesn't change the value of the 185 feet ... it only changes the UNITS.

Length = (185 feet) x (12 inches/1 feet) x (2.54 cm/1 inch) x (1 meter/100 cm)

Length = (185 x 12 x 2.54) / (1 x 1 x 100) (feet-inch-cm-meter / feet-inch-cm)

Length = 56.388 meters

c. magnitude and direction