How do you convert grams to ounces and how do you convert ounces to grams?

well, I am going to do this the hard way based on my answer to the last question.

You know now about 2.20 lbs/ kg
I also know 16 oz/lb
I also know 1000 g/kg
so
say I have 550 g and want oz
550 g (1 kg/1000g)(2.20 lb/kg)(16 oz/lb)
g cancels
kg cancels
lb cancels
and I am left with oz
so
550 * 2.20*16/1000 = 19.4 oz
now I think you could do the reverse all right.