Decimals are hard!

“Kid should’ve realized that her answer needs to be smaller.”

How do you help kids monitor themselves in this way? Do you monitor yourself in this way when you’re doing math?

(Thanks, Ruth, for the submission!)

  • I always enjoy seeing when student’s write, “clearly wrong, but…” after an answer like that. There might be plenty of students who mentally make the observation, but don’t write the comment because they don’t see the utility in doing so.

  • Re: monitoring. I’ve thought about this but haven’t tried it out yet. We do lots of work with the estimation180 activities, and it’s always first “Give me an answer you know is too high/too low”. Could that be transferred onto a word problem? What about setting the bounds before the student even answers. Would 4,325 mph be way higher than his too high? Would that cause the student to reevaluate his answer? Would their intuition (that 4325 mph is impossibly high) override their math?