What If There Were No Hundreds Place?

Imagine a world with no hundreds place. We’d have to call it ten tens instead. But then, what would we call the thousands place? How would we read 9999? What if we added one more?

Rounding Numbers (But Not To 10)

What could we possibly do to make rounding more interesting for students who already get it? In this series, students consider how they might round to values other than “the nearest 10.” How, for example, do we round to the nearest 9? 7? 15?