How to change precision of a Quantity

Questions
1

Whats the best way to change precision of a Quantity ? For example, to round this Quantity

Quantity[2.567786, "Hours"]

I tried

%~N~1

as well as approaches using ReplacePart and MapAt (part 1), but to no avail. Attributes@Quantity show it is {HoldRest, NHoldRest, Protected, ReadProtected}, which should allow operations on the first argument (i.e the magnitude 2.567786). I’m using v10.0.2

EDIT: I figured out that I need the NumberForm function. For example

Quantity[2.1234567, "Hours"]~NumberForm~3

evaluates to
2.12 h

2

You can also consider SetPrecision:

SetPrecision[Quantity[2.567786, "Hours"], 2]

which we can use in calculations. NumberForm is meant only for final formatted output.

3

Thanks, +1 !