I have a recipe that calls for 1 lb of glutinous rice flour (mochiko), but I don't have a kitchen scale. Approximately how many cups would this be equivalent to?
Around 2.5 - 3 cups (2.8 exactly) but I doubt exactness is necessary for your recipe if your willing to guess by volume.
May I suggest investing in some scales they will only set you back £14 for some bog' standard ones which will work just fine for home use.
According to the blog Fox in the Kitchen, 1 cup of glutinous rice flour weighs 204 grams, or .45 lbs. So 1 pound would be 2.22 cups.
FYI, 204 grams/cup meshes exactly with what Bob's Red Mill says on its nutrition label for glutinous rice flour. So perfectly, as a matter of fact, that I wonder if that's where the blog listed above got it.