Use a conversion factor, 0.4536 kgs are in one lb so there's 72.576kg in 160 lbs. By multiplying by 1000 you get grams, so that's 72576 grams.
.160 ounces = 4.535 grams.
160
160 grams = 5.6 ounces.
160 grams = 5.64 ounces.
160 grams = about 5.644 ounces.
That is 908 grams
180 lbs = 81,646.6 grams.
0.25 lbs = about 113.4 (113.3981) grams.
6.5 lbs. = about 2,948 grams.
0.055 lbs equates to about 25 (24.94758) grams.
160 mg = 0.16 g