Ah, good catch -- I had just copied the OP. Changing it to bag instead of back doesn't seem to change much. It still oscillates between the right and wrong answ

Ah, good catch -- I had just copied the OP. Changing it to bag instead of back doesn't seem to change much. It still oscillates between the right and wrong answer, versus qualifying the 10.01 value as pounds, which has not yet given me the wrong answer (small sample size, of course).