Really Big Lights – A math problem

November 28, 2016October 10, 2018 by Jon Orr

Here’s a really big problem you can work on with your students this holiday season.

Act 1:
Show them this video and ask: What do you notice? What do you wonder?

After allowing them to voice their noticing and wonderings guide them to wonder: How big is that new light? How many times bigger is the big light compared to the old light? How many Really Big Lights would you have to put up to cover the same length as last year?

Act 2: Here are some images to help make some conclusions:

Guess: How long is the big light? How many times longer is the big light than the small light?

Reveal:

Guess: How many small lights are in one string that stretches 15 feet?

Reveal:

Work together to determine how many Really Big Lights would replace the string of 50 lights? What assumptions will you make?

Act 3: Reveal

Why might your calculated answer be different from the answer shown?

If you had 50 Really Big lights how long would could they reach? How many cars could you put in that garage?

Grab all files for this activity

You can see more info about the lights over at http://reallybiglights.com/

One Favourite, Two Fixes: Nov 5

November 5, 2016November 6, 2016 by Jon Orr

I need help! Every time I go through a lesson there is aways something I want to fix. Something that can be improved upon. Something that can get my students to think a little deeper about the math or something that can make my organization better, or class management better. Sometimes I can think of how to fix it, sometimes I know there is a fix out there and I can’t see it. That’s where you come in.

Each week I’m going to post one idea from my lessons that was my favourite and two topics that I need help on. Two topics I hope to fix. I’m hoping that in the comments or on Twitter you amazing readers can help me out with some hints, tips, and suggestions.

Favourite

For the last two weeks one of my class’s atmosphere seemed poisoned (see below). My favourite this week though helped restore (for a short time) that atmosphere back to where we have spent most of the year. Warm-ups to the rescue! Our warm-ups dive into our Everyday Math curriculum like nobody’s business. Sometimes they take 10 minutes, sometimes 20….and I’m ok with that. Each one has my class engaged for that time. This week my favourite was Dan Meyer’s Dueling Discounts.

The kids each had a copy of a $20 off coupon and a 20% off coupon. For each item I showed, I had them hold up their choice of coupon to use. I was loving that all students were actively engaged and WANTED to know which was the better deal. It was so nice to see this with my kids again.

First Fix

Like I said above, my class’ atmosphere has seemed poisoned for the last two weeks. Before that we had an amazing atmosphere…..all kids worked well together. They sat in random pairs everyday, they were engaged! Then a few things happened.

Outside of class somebody was texting things they shouldn’t to somebody else….VP said they are not to work together.
A new student was added and talks a lot
Two others can’t work together because of a fight they were in last week.

So now we don’t have the awesome —we all can work together and build off each other atmosphere I love and had. I’m looking for tips to try so we can re-create our atmosphere we started with. Any ideas?

Second Fix

In my grade 9 mfm1p class this week we worked on solving proportions through the Smart Car Smash activity.

After going through super gross lesson and seeing the kids smile and cringe at the same time it was time to practice our strategies. I gave out this sheet below.

This is where all the excitement for math was lost….”ah man, a worksheet”. Most students solved the problems. Some kids who were actively engaged with the first problem now were shut down. How can I keep the practice portion that I need but keep engagement up?

Thanks for reading. I would love your help. Share your suggestions on Twitter or below in the comments.

Helpful Fixes from Readers:

@MrOrr_geek Lose the worksheet. Post problems around the room to “walk and solve.” Worksheets with a twist. Allow to solve in any order.

— PylesofMath (@pylesofmath) November 6, 2016

Flippity Flip, Bottle Flip!

October 14, 2016October 10, 2018 by Jon Orr

How are all these middle schoolers/grade 9s landing these bottle flips?

Time for a #3Acts Task to add some math to this epidemic? Or is it just in the US? @MathletePearce ? @MrOrr_geek ? https://t.co/3MTI39dI6M

— Cathy Yenca  (@mathycathy) October 2, 2016

Before today I hadn’t seen any of our students doing this bottle flipping thing! But I had a feeling they had all done it before. Today we started an activity with watching trick shots of bottle flips and will end with us creating and solving linear equations.

I showed this video:

My students wanted to argue that some of the tricks were fake…. but they were glued to watching. They all had tried flipping bottles before and some said they were amazing at it.

I had a full water bottle with me and asked if I could flip this. They all shouted that it was too full. I tried flipping and it was a no go. So I cracked it open and drank a few gulps. “Nope….you still won’t be able to flip that Mr. Orr — too much water still.” Again, I tried flipping it and nope. Still not even close. “Mr. Orr you probably won’t be able to flip it even if it had the perfect amount of water.” So I took a few more swigs. “Still no good sir.” As I was chugging….someone yelled out for me to STOP! I did…..then flipped that bottle…. and…..Boom! The class was blown away!

I had them log into a simple Desmos activity that asked them to choose which bottle would be ideal for flipping.

Almost everyone had chosen yellow.

The next slide had them moving a line to show the water level and then having them estimate how many ml would be ideal.

Students were estimating between 100 and 200 ml.

“I think it’s 125 because that would be a quarter of the bottle. I think a quarter is the perfect amount of water.”

“I think it’s not 250ml because it has to be less than half…..but I think it’s not exactly half of that….so half of 250 is 125….but I’ll say 150ml.”

I shared all of their guesses:

They kept asking if they were going to get to flip any bottles?? I said, “This is math class….do you think we flip bottles in math class?”

Then I broke out the bottles.

Here is the plan. We are going to have a bottle flipping contest. Rules:

Draw a line on your bottle where you think the ideal amount of water should be. Determine how much water to put into it in ml.
When you know how much water you need record it on our chart….put exactly that much water in there.
You must use your bottle for the contest.

Here are some pics of them working on this first part.

We had just enough time in this class to determine our volume, fill the bottle to verify it met the line, and practice flipping for about 10 minutes.

Part 2: The Contest

Students complete in five one minute trials. Recording how many “lands” they get each trial.

We average those five trials to develop your “Landing” equation! Who was the winner? What does their graph look like?

We use that equation to solve some problems. How many after ____minutes? How long will it take to make 100 lands? What does the equation look like if you have a head start of 5 lands?

I’ve modelled this lesson structure after this Paper Tossing activity and ultimately after Alex’s Card Tossing activity.

Featured Comment:

Mason:

Well I am a middle school student and I go to chesnee middle school and I think that I just might show this to MY math teacher even though I don’t like math but you just made me want to like math. I’m in the sixth grade.

Pentomino Puzzles

September 30, 2016October 10, 2018 by Jon Orr

A few years ago I was introduced to a series of activities (through my then districts math consultant) that builds a driving need for students to create, simplify, and solve linear equations. I used the activity for a few years in a row while I taught grade 9 academic. Since then I had forgotten all about it (funny how that goes) UNTIL NOW!

The activity ran as a series of challenge puzzles around Pentominoes and a giant hundred grid chart.

Activity 1: Explore

Ask students in groups to choose this tile and place it on the hundreds chart so that it covers a sum of 135. The task seems so simple to start but unpacks some great math.

Allow them to determine this sum anyway they like.

I circulate and listen to their strategies. I give them very little feedback at this point. After a few minutes I choose some of those groups I heard interesting strategies to share..then let any other group share out their strategy.

Activity 2: Keep Exploring

I have them use the same tile and try again. Place the tile so that it covers a sum of 420. Listen to those strategies! Most groups that didn’t have a strategy before will try to adopt a strategy they heard last round. At this point most students will catch the strategy “If I divide the sum by 5, being like the average then I should have the middle number in the shape.”

This is where I stop and have a formal discussion as to why dividing by 5 here works? Will this always work? Will this always work with other shapes? What other shapes will this work with then?

We formalize the strategy.

Our big problem to start is not knowing where to place the tile. Let’s say I label the middle square n. What will the square immediately to the right of n always be? The left? The top? The bottom? Have them check this out by placing the tile repeatedly back on the grid.

Now let’s add all of those expressions up

The middle square must be a multiple of 5!!! I have them try this strategy out by throwing out another sum and have them place the tile.

Look at another tile!

We go back and outline that we could have chosen a different square to label n. Which results in a new equation and solves for different value…..but results in the same placement of the tile!!

We continue by me having them select different tiles, giving them sums, having them create equations and solving them. I love how hands-on this lesson is. Holding the tiles adds some “realness” which I feel drives the need to solve these equations.

However,

this year when I remembered this activity I wasn’t sure I still had the tiles kicking around (I found them later). I immediately made a digital version with Explain Everything.

The digital version gives each student their own copy and while working in groups can chat about what strategy worked and what didn’t. Before on the paper version….only one student could hold the tile. Also, when students have to voice their strategy through Explain Everything they have to have careful thought. They think about the words they want to use. We this careful thought they get to make their thinking visible for me!

One new addition to the activity I get to make here is that they can create their own pentomino…..and then their own puzzle to share with their classmates.

Since then I also created the activity with some help from the team over at Desmos

Click to access and rune the teacher.desmos.com activity

I love their new conversation tools….I get to pause the class and discuss when needed!

Students can even sketch their new tile and create an expression to match!

Desmos even added some nice extension questions. Love it!

In the future the next time I explore this lesson I see a blend of hands on tiles with digital support. I think having the best of both worlds here can pack a powerful 1-2-3-4-5 punch!

Pick your favourite!

Download the Explain Everything Pentomino Puzzles .xpl file.

Access the Desmos Activity

MFM1P

Really Big Lights – A math problem

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