ABSTRACT
This chapter discusses common mistakes in math instruction and explains the misunderstandings behind them. Jane was teaching her children different units of time and how to tell time from an analog clock. When quarter is used to measure time, it's still 1/4, only it's 1/4 of an hour. The confusion lies in fact that quarter, as a coin name, has come to be associated with 25 cents for many children. What Jane said here isn't a conceptually rigorous way of teaching children how to tell hours and minutes. Jane has a model analog clock in her classroom that allows her to move its two hands freely and demonstrate whatever time she wants to show to her children. The whole idea is that hour hand doesn't "jump" from 6 to 7 at one single moment and then stays immobile for next full hour. Children starting to learn how to tell time on an analog clock are just like this exchange student.
