# Asking Open Questions, why it matters for math

I’ve been asking open questions and I think you should too. Maybe you already are. If so, please reply to this blog with some of yours so we can share! 🙂

The other day, I started my Algebra 2 class by asking students to think of 10 numbers. I know I’m not a mind reader, but if what they say is true and 90% of communication is non-verbal, then I was 90% reading their minds…

I knew they had easily thought of their numbers as I continued to give instructions, “draw a number line and try to think of numbers that would represent the number line… .” Their faces fell as they had to rethink this. They were once again happy and satisfied when I demonstrated and started to draw my number line and scaled it -5 to 5 and started to plot points above the number line at -3, 1, etc. I asked them to think of maybe some negative values, maybe a decimal or a fraction, maybe a mixed number… I asked them to try to think of numbers that represent numbers they’ve learned about over the years.

They all started to write down new numbers. So, at this point, one of the great things about open questions was that everyone was involved, not just the kids who could ‘figure it out’. Everyone could think of numbers. Everyone understood a number line and negatives and fractions and decimals – this was an algebra 2 class, after all. This was feeling easy for them. They great thing is that they could all have different numbers and all be ‘right.’ Satisfying.

So, even better, they were hooked. I asked if there were any other interesting values they could think of. One student said, “Pi!” That was perfect. I marked it on my number line on the board. Many kids marked theirs. I said what about 2π? or -π? or 1.5π? Any others? Wait…. nothing, that’s okay, I’d leave radicals for another conversation.

Then I asked, “What is my number line missing? What am I not including?” They had to think. I asked about my domain. They said it was very small. I agreed that I had only included small numbers. Then I asked, who picked the largest number? Hands went up. The largest ended up being only 100, the smallest -100. I asked if we should have larger numbers or infinity symbols somewhere.

Anyway that wasn’t the point, but it was fun. So, then I marked a new number on my number line, at about 2.7. I asked if anyone new what the value was. They shouted out guesses, finally I heard 2.7!. I said, yes, that’s very close! Then I wrote the expression lim as x→∞ of (1+1/x)^x on the board, over the point. From there, we talked about limits, what happens as x gets larger, we made a table of values and tried larger and larger numbers for x, only to see that y was changing less and less and moving towards, 2.718···. Then I said this is a special value, just like π, and it’s called the natural number, e

I’ve introduced and derived e with my students many times over the years. The difference this week, was that they were all hooked, all involved, they all had money on the table (intellectually speaking). Everyone was writing and thinking. You could see it from the expressions on their faces.

In Algebra 2, asking open questions feels so important to me. It’s a tough class to teach. There’s a lot of material and a short amount of time. There’s a wide range of students in the room – varied grades, varied backgrounds and varied attitudes towards learning math. Open questions allow for many entry points which generate stronger feelings of success and inclusion.

The new standards seem to want us to go deeper than we have in the past and students need to think more critically. Engagement needs to be high. Asking open questions really helps them engage and think and stay tuned to see what happens next. Even if what happens next is a bit of traditional lecture and on to some problem solving. They enter it with more curiosity and more confidence.

I’ve been doing more open questions this month and I’m seeing a change in the culture in the room. I have to thank the great educators and researchers who introduced these ideas to me at CMC-North this past December. Steve Leinwald in particular, Dan Meyers and Michael Fenton and the dream team at Desmos. My teaching has transformed (see It All starts to Gel…  http://wp.me/p73p86-2)

Resources for me have been:

• NRich website
• The book: More Good Questions, Great Ways to Differentiate Secondary Mathematics Instruction, by Marian Small and Amy Lin  link to amazon
• The book: Styles and Strategies for Teaching High School Mathematics, by Thomas, et al., 2010 link to amazon

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