How Many Will There Be? Triangles Within Triangles

A triangle splits and splits and splits again. How many will there be in step 20?

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?

How Many Ways: Order of Operations 1

How many different ways can you make this math statement true using only the digits one through nine?

Calculators, Patterns, and Multiplying By Decimals

Before teaching students the procedure for multiplying with decimals, how much can they intuitively glean from a structured play session with calculators?

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?

Doubling Dollars

Say you have a dollar. Say you can double that dollar each day: $1, $2, $4, and so on. How long will it take to reach… one million dollars? Not as long as you might think!