unit km = 1_000<m>
unit cm = .01<m>
unit mm = .001<m>
unit inch = 0.0254<m>
unit ft = 12<inch>
unit yd = 3<ft>
unit mi = 5_280<ft>
unit min = 60<s>
unit hr = 60<min>

x := 5<kg*m/s>
y := 10<kg>
say "$(x * y)"
say "$(x / y)"
// say "10% of $x = $((10%).of(x.scalar()) * x.units())"
say "2x of $x = $(2. * x)"

say "5ft + 1m = $(5<ft> + 1<m>)"

vel := 100<mi/hr>
say "100<mi/hr> = $vel"
say "$vel in km/hr = $(vel/1<km/hr>)"