Hello. I am new to engineering and to imperial units, and currently learning by doing some exercises. I'm stuck on the following conversion: 0.04 g / min x m^3 -> lbm / hr x ft^3 I figured it like this: 0.04 g / min x m^3 x (60min/1hr) x (1m/35,314)^3 x (1 lbm / 454g) = 1,49x10^-4 lbm / ft^3 x hr However, the author of the book gives the following solution: 0.04 g / min x m^3 x (60min/1hr) x (12in/1ft)^3 x (1 lbm / 454g) = 9.14 lbm / ft^3 x hr It really lost me, why (12in/1ft)^3 its supposed to cancel out m^3? He does the same on a similar exercise converting cm^2 with (12in/1ft)^2. Thanks for your time and help.