so you have 3/4x2/3 because it's 2/3 of the bag left, so you find the least common denominator (bottom number of fraction), which in this case is 12, so you find how you get to 12 for each of the bottom numbers, so x3 on the first one, and x4 on the other one. then you multiply the top numbers by what you multiply the bottom ones by, so it would be 9/12x8/12 you then multiply both numbers so 72/144 and then you simplify that to 1/2 so it's 1/2lb.
