joe uses 3 5/6 feet of ribbon to wrap one package. how much ribbon does he use to wrap 12 packages ?

3 5/6 * 12 = 3*12 + 5/6 * 12 = 36 60/6 = 36+10 = 46

or,

3 5/6 = 23/6
23/6 * 12 = 23 * (12/6) = 23*2 = 46