Essential IM

An AI-generated short discussion of an Illustrative Mathematics lesson to help educators prepare to teach it. 

The episode is intended to cover: 
  • the big mathematical ideas in the lesson
  • the main activities students do
  • how to make it interesting for young people
  • possible misconceptions and how to deal with them.

What is Essential IM?

Lesson by lesson podcasts for teachers of Illustrative Mathematics®.

(Based on IM 9-12 Math™ by Illustrative Mathematics®, available at www.illustrativemathematics.org.)

Speaker 1:

Ever feel like spreadsheets are just rows and columns, you know, just craving to be filled with student boredom?

Speaker 2:

Mhmm.

Speaker 1:

What if I told you they're actually secret weapons

Speaker 2:

Right.

Speaker 1:

For unlocking algebra 1? Okay. Today's deep dive is all about turning lesson 8 Alright. Specifically spreadsheet shortcuts

Speaker 2:

Yeah.

Speaker 1:

Into a smash hit for your classroom.

Speaker 2:

That's good.

Speaker 1:

So we're diving into algebra 118 lesson teacher guide 2 dot PDF.

Speaker 2:

Okay.

Speaker 1:

And let me tell you, the curriculum creators were clever with this one.

Speaker 2:

Really? How so?

Speaker 1:

They use a classic birthday math trick as a hook Oh,

Speaker 2:

okay. To

Speaker 1:

introduce cell referencing.

Speaker 2:

That's a I mean, that's really effective

Speaker 1:

Yeah.

Speaker 2:

When you think about it.

Speaker 1:

It is.

Speaker 2:

You ask students to, you know, input their birth month and day

Speaker 1:

Right.

Speaker 2:

Into this, like, seemingly simple spreadsheet.

Speaker 1:

Yeah.

Speaker 2:

And unbeknownst to them Yeah. It's carefully crafted formula disguised as a magic trick Right. Uses those inputs to eventually, like, spit out a number Uh-huh. That magically reveals their birth date.

Speaker 1:

Okay. That sounds really cool, but how does it actually work?

Speaker 2:

So let's imagine a student's birthday is January 5th.

Speaker 1:

Uh-huh.

Speaker 2:

In cell a one, they input 1 for January.

Speaker 1:

Okay.

Speaker 2:

In b one, they put 5 for the day. Mhmm. Now the magic unfolds in the formula.

Speaker 1:

Okay.

Speaker 2:

In cell c 1, you might have something like a 12. Right. In the next cell, d one, you continue the pattern using another formula.

Speaker 1:

Okay.

Speaker 2:

Let's say c 1+5 and so on. Okay. Each step kinda builds on the previous one. Right?

Speaker 1:

Right.

Speaker 2:

Yeah. Eventually, including their birth date within the final result.

Speaker 1:

So it's not just about that final trick at the end.

Speaker 2:

Exactly.

Speaker 1:

It's about the students seeing how

Speaker 2:

Yeah.

Speaker 1:

Changing the values in cells a 1 and b 1 Right. Directly impact that final result.

Speaker 2:

It sparks that initial curiosity Yeah. Like a sneak peek into the power of cell referencing.

Speaker 1:

Yeah. For sure.

Speaker 2:

But the true magic

Speaker 1:

Yeah.

Speaker 2:

Happens when we transition from this, like, playful trick Right. To a core algebraic concept.

Speaker 1:

Okay.

Speaker 2:

Equivalent ratios.

Speaker 1:

So this is where the lesson shifts Yeah. From just a fun activity That's Right. Powerful learning tool. Right? Absolutely.

Speaker 1:

Because instead of just presenting tables of numbers

Speaker 2:

Mhmm.

Speaker 1:

This lesson has students use a spreadsheet to discover Right. And understand equivalent ratios.

Speaker 2:

Think about it.

Speaker 1:

Okay.

Speaker 2:

In a traditional table

Speaker 1:

Mhmm.

Speaker 2:

The relationship between those numbers might seem static.

Speaker 1:

Yeah.

Speaker 2:

But on a spreadsheet Yeah. Students can manipulate those numbers

Speaker 1:

Right.

Speaker 2:

Change one cell

Speaker 1:

Mhmm.

Speaker 2:

And instantly see the impact on the others.

Speaker 1:

Yes. So they go from Exact. Passive observers to active participants

Speaker 2:

Yes.

Speaker 1:

In uncovering these mathematical relationships.

Speaker 2:

You've hit the nail on the head.

Speaker 1:

I like that.

Speaker 2:

And the beauty of this approach is it seamlessly integrates technology Right. While still emphasizing Mhmm. The fundamental concepts.

Speaker 1:

Yeah.

Speaker 2:

For instance k. Students are tasked with

Speaker 1:

Yes.

Speaker 2:

Finding missing values in a table of equivalent ratios.

Speaker 1:

Right.

Speaker 2:

So this not only reinforces their understanding of ratios

Speaker 1:

Mhmm.

Speaker 2:

But also prompts them to kinda decipher the underlying rule.

Speaker 1:

Mhmm.

Speaker 2:

Connecting those numbers, it's like they're piecing together a puzzle.

Speaker 1:

Right.

Speaker 2:

But instead of cardboard pieces

Speaker 1:

Yeah.

Speaker 2:

They're manipulating numbers and formulas. And this sets the

Speaker 1:

stage for understanding Yeah. How formulas actually work in a spreadsheet. Right? Exactly. And the guide cleverly highlights Okay.

Speaker 1:

A common misconception

Speaker 2:

Okay. Students might have about recursive formulas.

Speaker 1:

Oh, you mean, like Yeah. The idea that each row builds upon the one before it?

Speaker 2:

Exactly.

Speaker 1:

Like, instead of always going back to the original starting values

Speaker 2:

Right.

Speaker 1:

They need to use the results from the previous calculation.

Speaker 2:

Precisely. Yeah. It's a subtle Right. But crucial concept.

Speaker 1:

Okay.

Speaker 2:

And the guide suggests using visual aids

Speaker 1:

Okay.

Speaker 2:

To help students grasp this.

Speaker 1:

Yeah.

Speaker 2:

Imagine using, like, color coding or arrows Yeah. To visually link the cells involved in a formula.

Speaker 1:

Oh, I see. So Yeah. Instead of just seeing, you know, a string of numbers and symbols Mhmm. They can actually visualize the relationship between the cells. Yeah.

Speaker 1:

I can see how that would be a game changer

Speaker 2:

Right.

Speaker 1:

For visual learners.

Speaker 2:

And speaking of visual learning

Speaker 1:

Yeah.

Speaker 2:

Remember that birthday trick we talked about? Yeah. The guide mentions a digital version of that activity.

Speaker 1:

Now that's interesting. Yeah. How does that work?

Speaker 2:

Well, in the digital version Okay. Students input their birth date.

Speaker 1:

Mhmm.

Speaker 2:

And the spreadsheet does the calculations in real time.

Speaker 1:

Oh, wow.

Speaker 2:

So they can experiment with different birth dates

Speaker 1:

Okay.

Speaker 2:

And actually see those changes reflected immediately.

Speaker 1:

So instead of passively following steps on paper and getting instant feedback. Exactly. I like it. And because the digital version handles, like, the heavy lifting Yeah.

Speaker 2:

Calculations Mhmm. Students are free to focus on Yeah. The underlying patterns Right. And the magic of cell references.

Speaker 1:

This is reminding me of another key feature of this lesson. Okay. The fill down function.

Speaker 2:

Oh, yeah.

Speaker 1:

It's like a superpower for spreadsheets.

Speaker 2:

It certainly is.

Speaker 1:

Like, you can just

Speaker 2:

The guide uses another activity Okay. With equivalent ratios Mhmm. To introduce this.

Speaker 1:

Okay.

Speaker 2:

Imagine this. Students start by, like, writing a formula in one cell

Speaker 1:

Yeah.

Speaker 2:

And then with a simple, like, drag or click Uh-huh. They can apply that same formula k. To an entire column of cells.

Speaker 1:

So it's, like, super, Yeah.

Speaker 2:

Incredibly efficient.

Speaker 1:

Efficient. Yeah. Right. But I do wonder

Speaker 2:

Yeah.

Speaker 1:

Could this lead students to make mistakes?

Speaker 2:

That's a great point.

Speaker 1:

Yeah.

Speaker 2:

If they don't fully understand the formula Right. Exactly. They're replicating.

Speaker 1:

Right. They're just like, oh, I can just drag this down.

Speaker 2:

Yeah. And it underscores the importance of having students engage with Yes. The why behind the formula Yeah. Not just the how.

Speaker 1:

Right. Not just the mechanics of it.

Speaker 2:

And what's fascinating Uh-huh. The guide acknowledges that students might come up with different

Speaker 1:

Okay.

Speaker 2:

But equally valid formulas

Speaker 1:

Okay.

Speaker 2:

To achieve the same result.

Speaker 1:

Interesting.

Speaker 2:

So some might gravitate towards, you know, a recursive formula, the one that references the previous cell Mhmm. While others might discover an explicit formula

Speaker 1:

Right.

Speaker 2:

That directly links back to the initial values.

Speaker 1:

So it encourages them to find their own kind of problem solving

Speaker 2:

Exactly.

Speaker 1:

Pathways.

Speaker 2:

Yeah. And it reinforces that idea that Yeah. In math, there isn't always a single right way Exactly. To approach a problem.

Speaker 1:

I'm curious, though.

Speaker 2:

Yeah.

Speaker 1:

We keep mentioning recursive formulas.

Speaker 2:

Mhmm.

Speaker 1:

Can you break down why they're so important Yeah. Absolutely. For students to grasp.

Speaker 2:

Recursive formulas are fundamental

Speaker 1:

Okay.

Speaker 2:

In math, particularly in algebra and beyond. Okay. They form the building blocks for understanding more complex concepts later on.

Speaker 1:

Mhmm.

Speaker 2:

Like, you'll find students will encounter them time and time again.

Speaker 1:

So by mastering them now

Speaker 2:

Right.

Speaker 1:

They're setting themselves up for success

Speaker 2:

Precisely.

Speaker 1:

In future math courses.

Speaker 2:

And what this lesson does so brilliantly is it makes those formulas Yeah. Tangible and visual. Okay. Students can see how changing one value ripples through the entire spreadsheet.

Speaker 1:

Right. Like a domino effect.

Speaker 2:

Yeah. Making the concept of recursion less abstract Right. And more concrete.

Speaker 1:

So they go from memorizing formulas to truly understanding them.

Speaker 2:

Yes. The cause and effect.

Speaker 1:

The cause and effect relationships within them.

Speaker 2:

This is pure gold.

Speaker 1:

This is great.

Speaker 2:

And it highlights the true power of spreadsheets as teaching tools.

Speaker 1:

Mhmm.

Speaker 2:

They're not just about crunching numbers.

Speaker 1:

Right.

Speaker 2:

They're about making math dynamic and engaging.

Speaker 1:

It's about bringing those abstract concepts to life.

Speaker 2:

Exactly.

Speaker 1:

Speaking of which, the guide emphasizes going beyond the lesson itself.

Speaker 2:

Yeah.

Speaker 1:

How do they suggest extending the learning?

Speaker 2:

Well, they encourage teachers to, you know Yeah. Challenge students to create their own patterns using formulas

Speaker 1:

Okay.

Speaker 2:

Or even come up with their own spreadsheet math tricks.

Speaker 1:

Oh, that's fun.

Speaker 2:

Yeah. So it's about giving them the tools

Speaker 1:

Right.

Speaker 2:

And then empowering them to explore and discover on their own.

Speaker 1:

So you could even have them Exactly. Use spreadsheets to you Imagine

Speaker 2:

the excitement Yeah. When students realize they can use spreadsheets to model Yes. Real world scenarios.

Speaker 1:

So, like, they could calculate the cost of a trip or something?

Speaker 2:

Absolutely. Yeah. Or track their favorite sports team stats.

Speaker 1:

That's a good idea.

Speaker 2:

Or even design a simple video game.

Speaker 1:

Like Right. The possibilities are endless.

Speaker 2:

The possibilities are truly endless.

Speaker 1:

It really opens up a world of possibilities, doesn't it?

Speaker 2:

It does.

Speaker 1:

Now while we've been, you know, laser focused on the student experience Mhmm. I'm curious about your perspective as an educator. Sure. What, key takeaways

Speaker 2:

Yeah.

Speaker 1:

Would you offer teachers?

Speaker 2:

1st and foremost, I think the guide does an excellent job

Speaker 1:

Okay.

Speaker 2:

Of anticipating potential pitfalls.

Speaker 1:

Like what?

Speaker 2:

Like that misconception around recursive formulas.

Speaker 1:

Right.

Speaker 2:

By highlighting this early on. Yeah. Teachers can address it proactively Mhmm. Perhaps by incorporating those visual aids we discussed.

Speaker 1:

Yeah. It's about, like, guiding students toward those moments and minimizing confusion.

Speaker 2:

But beyond that Yeah. I'd say the true strength of this lesson Okay. Lies in its adaptability. In what way? While the guide provides a solid framework

Speaker 1:

Mhmm.

Speaker 2:

Teachers can easily tailor the activities

Speaker 1:

Okay.

Speaker 2:

To match their students' interests

Speaker 1:

Right.

Speaker 2:

And learning styles.

Speaker 1:

Well, if I have a class that's, you know, super into video games, I could have them create a spreadsheet that Absolutely. Like, tracks character stats or something like that.

Speaker 2:

Or if you have a class interested in, like, entrepreneurship Okay. They could model the costs and profits Mhmm. Of a hypothetical business.

Speaker 1:

So it's about making those connections between math

Speaker 2:

Yes.

Speaker 1:

And the real world.

Speaker 2:

And the real world and making it meaningful to them.

Speaker 1:

It's about showing them that algebra isn't Yeah. Confined to textbooks. It's a tool they can use to understand the world around them.

Speaker 2:

Precisely.

Speaker 1:

This has been great.

Speaker 2:

And that's what makes this lesson so powerful. It's not just about teaching, like spreadsheet mechanics. It's about fostering a deeper understanding Yeah. Of mathematical concepts

Speaker 1:

For sure.

Speaker 2:

And empowering students to see themselves as mathematicians.

Speaker 1:

And who knows? Right. Maybe we'll even spark a lifelong love Yeah. Of spreadsheets in the process.

Speaker 2:

Yeah. Wouldn't that be something?

Speaker 1:

A big thank you to the authors of Illustrative Math for this insightful lesson.

Speaker 2:

Yes. Absolutely.

Speaker 1:

So the next time you open up a spreadsheet, remember, it's not just about rows and columns. Right. It's about unlocking patterns.

Speaker 2:

It's about making it fun. Yes. It's about making it engaging.

Speaker 1:

And empowering your students to see the magic of math.

Speaker 2:

Absolutely. Yeah.

Speaker 1:

This has been a fascinating deep dive. Until next time.