It goes with the numerator

Unit conversion

unit conversion is very simple. Only you have to know is about the relation between the units.

If you try to convert 2km/h to mil/min then you have to know the relationship between km and mile.

1 km = 0.625 mile      ( 1 mile = 1.6 km)

1 hour = 60 minute

Now, let's convert unit.

2 km/h =  2 times km  divided by hour

= (2 km )/ h

 = (2) (1km) / (1h)  *** the unit "km"  represents 1km and unit "h" represents 1h : this is core concept of unit conversion ***

 you know the relationship between the units, therefore you just plug in the previous unit to the  wanted unit.

= (2) (0.625 mile) / (60 min)  ; rearrange the numbers and units.

= [ (2 x 0.625 )/ 60 ] ( mil/min )

= 0.02 mil/min   

All the other unit conversions are using the same principle. If you practice several unit conversion with this method you will get used to this method.

Hope this help you.

To add a little explanation to the previous answer, the fraction bar between the 'm' and the 'hr' acts as a set of parentheses, so when you see m/hr, you are can read it as (m/hr).  And when you have a number outside a set of parentheses, it is understood to multiply the whole contents of the parentheses.  For example:

3 ( 7 + 4 ) means 3 times 11.

And 3 (1/2) means 3 times a half, not 3/6 which would still be 1/2.