Given that 1 u. s. dollar = .6536 british pound
1 british pound = 3.1517 new zealand dollars and
1 new zealand dollar = .8262 australlan dollar.
determine how many u. s. dollar are in 10 austraalian dollars

(10 Aus) x (1 NZ / 0.8262 Aus) x (1 Brit / 3.1517 NZ) x (1 US$ / 0.6536 Brit) =

(10) / (0.8262 x 3.1517 x 0.6536) = US$ 5.87  (rounded)

Notice that each of the underlined fractions in the top line is equal to " 1 ".
So they change the units of the " 10 AUS " but they don't change its value.,