convert 6.5*10^-3 g.cm/h to kg m/s
6.5*10^-3*10^-2/3600s=1.8*10^-8
You have missed the point on unit conversion. KEEP THE UNITS.
6.5E-3 gcm/hr*1kg/1000g*1m/100cm*1hr/3600s
notice the units divde out, and you are left with kg m/s
Now do the math
6.5E-3*1E-3*1E-2*1E-3/3.6 kg m/s
6.5/3.6 E -8 you are right.