Dan Meyer made those word famous in his 2010 TED Talk, “Math Class Needs A Makeover”. That one of the large stumbling blocks for students — and, I suppose teachers sometimes — is an impatience for irresolution. That somehow not getting an answer in the time it takes to boil an egg means some kind of failure or inability to do/understand mathematics. This myth is not only false, it has done almost irreparable damage to how/why mathematics gets taught in schools.