Playlist: Bookmarks

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?

Place Value (Beyond Base 10)

Place value is something we cover in elementary school. It seems simple, but I’d wager that very few adults really understand the topic. I sure didn’t until I worked with non-base-10 number systems in college. Your students can get a taste of this mind-boggling experience by imagining what it would be like if we didn’t have the number 9. What would each digit represent then?