Ketchup (Guess vs. Estimate)

I had breakfast at a restaurant this weekend and noticed the ketchup bottle on the table. You know, the bottles that are red plastic? That are supposed to appear full? I always get a kick out of these bottles. Here's why..

I immediately wonder how much ketchup is in the bottle?

Take a second to think how almost any answer is pure GUESS.

WHAT information would you want to know here to make an estimate and not a guess?
HOW would you go about getting the information to make an estimate and not a guess?

The second I do this...

I know WAY more information. It's no longer a guess.

Think of other senses that could be used to make a better estimate. 
*One scenario would be something along the lines of me watching the customer(s) before me to see how they held the bottle. How did they shake the bottle? How many people at the table used ketchup and how much?
But that's just plain weird...

Sure, pick up the bottle. Formulate an answer and be ready to back it up with a reason. Don't skip this reasoning part. The bill depends on it!

Let's now move to the answer. Let's say we have more information now.
How would you describe your answer?
How might someone else describe their answer?

Could we say any of the following?

• It's half full.
• It's about 3 squirts.
• It's two-thirds empty.
• It's about a pound.
• I could eat 5 french fries with that.
• It's about 8 ounces.
• [insert other]

Here's where specificity matters. How should we agree to quantify the amount of ketchup in the bottle? Should we agree at all?

This ketchup bottle context is one of the simplest contexts I've come across in awhile. Here's why:

• The question is straightforward.
• You demand more information to do anything better than a pure guess.
• With one small piece of information, your guess should now be an estimate!

In case you're wondering about the time of day, I don't think it really matters here. The bottle was about a quarter full and this was at breakfast time. It's not like someone went around the night before and filled every ketchup bottle. Which begs the question: 

Is it more efficient for an employee to go around lifting all of the ketchup bottles to determine if it needs refilling or should they just wait until a customer says, "The ketchup bottle is empty, can we get a new one?"

Why haven't you seen more Estimation 180 challenges that deal with weight, density, etc? They're tricky to capture. I wish I could fix that, but I digress. I'll put that onus on you. 

My charge to you is:

No matter what grade level you teach, bring in an item like the ketchup bottle. Ask a simple question where the answer is pure guess and students demand more information to make an estimate. Literally, keep track of all the questions/demands students formulate. Report back.

Classroom (or lesson design) application:

• Design lessons with less. (notice "less" is in "lessons")
• Ask straightforward questions that demand more information.
• Use information to move away from guesses and into estimates.
• Is it more effecient to go around asking our students what they're stuck on and re-filling them with information or should we wait until they realize their stuck and we help them get unstuck?

Lots for me to think about. Feel free to chime in with some advice. Thanks.

Ketchup,

1248

P.S. This reminds me of one of my favorite jokes:

A momma tomato and baby tomato are walking down the street. The baby tomato falls behind because it's going slower. The momma tomato turns around and stomps on the baby tomato, yelling "Catch-up!"

The Ultimate Task for Vertical Planning: Stacking Cups

This past week, I submitted a speaker proposal for NCTM 2016 in San Fransisco. The proposal is for a Grade 6-8 Burst (30 minutes) with the exact same title as this blog post: The Ultimate Task for Vertical Planning: Stacking Cups. I figure if I don't get accepted, at least I can share my thoughts here and you all can help spread the word about my idea if you think it has potential. If it does get accepted, I look forward to giving an update a year from now at NCTM. Here's my session description:

Who says you can't use the same task each year? Come see why Stacking Cups might be the single best secondary math task to get teachers at your school, district, or state to see the importance and necessity of vertical planning. Use tasks that utilize connections from the previous year and extend the mathematics each year. Work smarter, not harder. 

Let's first back up a bit. I attended Alex Overwijk's session at NCTM Boston a few weeks back. I had already read his awesome blog post "Open Strategy Cup Stacking" and knew there are multiple teaching moments with Stacking Cups. I remember teaching Math 8 a few years ago and getting a lot of use out of Stacking Cups as you can see a couple times here and here. I was preparing for a training with math teachers from grades 6-12 and THAT's when it hit me: I could have a room full of math teachers from grades six through twelve and they all could:

• be working on this task
• see the different skills and tools necessary for solving
• know the expectation of each grade level

I've heard comments from teachers numerous times like, 

"Well, if they do File Cabinet in 6th grade, I can't do it in 7th grade with my students."

"If they've done Stacking Cups in Math 8, then I can't do it in Algebra."

"If the 5th grade teachers use Estimation 180 with students, then I can't." 

YES! YOU CAN! It's called vertical planning.

YES, YOU CAN! Instead, let's ask different questions like, "How can we use the same task to extend the mathematics each year?" and  "How can we make connections to prior learning from the previous grade level?"

Let's work smarter, not harder.

I will spend the rest of this blog post highlighting each grade level and suggested uses for Stacking Cups. It won't be complete or the final version as this is through the lens of one person. I'm confident, with your help and critique, we can make it even better.

Math 6
Question: How many cups do we need to stack (alternating) to reach someone's height?
We talk about rate. We organize our information on a number line, in a table, using a tape diagram, etc. We explore the rates using various models.

Math 7
Question 1: How many cups do we need to stack (alternating) to reach someone's height?
We continue the conversation started in Math 6 revolving around rates, using constant of proportionality. All of this can be represented in a table, as an equation, and in a coordinate plane.

Question 2: How many cups do we need to stack (consecutively) to reach someone's height?
We now shift our thinking a bit where there is still a constant increase with each cup, but there is an initial amount (the cup handle). Students explore how to write an equation to represent this situation and solve it.

Question 3: What would be possible dimensions of a box that would contain the cups to stack to someone's height? Which dimensions would be the most cost effective?
Imagine students understanding surface area and volume and how they're related to each other, especially if we model with mathematics, by identifying variables such as:

• cardboard cost
• delivery truck capacity 
• store storage sizes
• consumer trends with buying cups
• more

Math 8
Question 1: How many cups do we need to stack (consecutively) to reach someone's height?
Similar to question 2 in Math 7. However, we extend the mathematical understanding as we explore constant rate of change (slope), input and output, linear, and how our situation can be represented in the form y = mx + b.

Question 2: When will two stacks of different sized cups be equal in height and have the same number of cups in each stack?
We introduce students to linear systems using this task. Students can organize the information about each cup in a table. We can extend prior knowledge to represent the situation using graphs, equations, and functions.

*By the end of Math 8, it might be helpful to mention (at least informally) to students the significance of discrete functions.

Algebra
We tighten up the math (both questions) previously learned in Math 8. How can we extend the mathematics. Add more challenging situations like the stacks start on different objects like desks, boxes, etc.
Question 3: How many cups would we need to stack in a triangular formation to someone's height?
This questions really extends the mathematics for students, but we can still use the tools they've learned from previous grades. Maybe students start by organizing the data in a table. Maybe they graph the data and notice it isn't linear. Maybe we can use desmos with sliders or a line of regression to explore quadratics.

Beyond Algebra and Geometry:
I'll admit this is where I'm a little rusty and would need you high school pros to jump in and contribute. I think with the triangle stacking, it can be taken from quadratic to a divergent series. I've also seen high school teachers come up with the following representations:

Al Overwijk also stacked cups in a triangular pyramid which is awesome.

Let's keep this vertical planning going. If you would like a couple charges, here you go:

Go to your site and/or district and push for Stacking Cups to be a signature task at all sites and secondary grade levels. Help support your colleagues with vertical planning. Report back.

Look for other tasks out there like Robert Kaplinsky's Hot Dogs or Dan Meyer's Penny Circle or Mathalicious' Wheel of Fortune or Graham Fletcher's Water Boy that can be used with vertical planning. Report back.

Vertical,
432

A Jammed Rational-Irrational War, Stacking Cups Week

Some cool stuff happened this week. Well at least I think it was cool.

Monday: 

One of my math fellows was observed by other math teachers from our district. He was starting a new unit with rational and irrational numbers, focusing on 8.NS.1 and 2. I might be wrong, but pretty dry stuff… here’s how we spiced it up a little.

We did a pre-assessment using the Post-It Plus app. Yes, my obsession with Post-It notes has gone to a new level: digital. We created a file within the app, posted it on his Haiku calendar, and had the students download the file into their app on their iPad. 

Students first worked individually to sort the terms from least to greatest for a few minutes. Since his students are grouped in fours, they then narrowed it down to one iPad screen they thought was most accurate. (Quick demo)

*Reflection: we should have had students paired up first, discuss, and narrow it down to two screens for the entire group. Next, the whole group of four students would discuss and narrow the two iPad screens down to one screen for the group.

Once each group settled on a screen they felt most confident with, they took a screenshot and uploaded their group’s screenshot to the Padlet page my fellow created for them.

My fellow used this Padlet page to assess the overall climate of the class (without teaching them a single thing). He used this real-time data to have some really rich conversations and share-out of ideas from students.

Remember to tell students:

• It’s okay if you’re wrong. 
• Make your best guess.
• I just want to see what you already might know.

Flash forward to Friday:

The previous weekend I asked the same fellow what he thought about playing War with rational and irrational terms. Side note: I play a few card games with my young son and one of them is War. My fellow thought the idea was epic. He ran with it. Here how he made it awesome:

• He made these awesome cards.
• Some values had multiple representations
• Printed them out on card stock.
• Made a graphic organizer for students.
• Each group of four was broken down like this:
• 2 people played War while the other 2 people recorded and were the judges.
• The next round, the roles were switched.
• There were 3 rounds.
• Each round was 6-10 minutes
• He stopped class and made a spectacle whenever two students were at war.
• The third and final round was between the winners of the first two rounds.

I asked if I had his permission to share the cards and he said, “Sure.”

Tuesday:

Another fellow asked me to model Stacking Cups in their first period class, which ran less than 45 minutes. My fellow requested I complete the task with students in one period. I explained that I’ve never “finished” the task in one period because there is so much to explore and learn in the task. I respected the request and  tried to cram it into one period. I spent too much time launching the task. 

Act 2 (the best part) felt rushed and we still didn't finish. My fellow and I debriefed and made some adjustments so she could finish it with her next period. She stuck to the adjustments and did a fantastic job facilitating the task. The students were doing awesome and amazing math during Act 2… and what do you know? The class was over. I love that my fellow was going to revisit the task the next day. Could we have spent another day on the task? Yes. It’s a starting point and I’m very proud of my fellow for trying out something new and doing a great job. I’d say the sweet spot would be one-and-a-half days for this task...
*Side note: I encourage you do styrofoam cups earlier in the year, and use Stacking Cups throughout the entire linear systems unit.

Thursday:

Another teacher wanted me to model Stacking Cups as well. When we sat down to plan, she was totally cool with spending one-and-a-half days on the task. Great news!

I launched the task, used a Padlet page to capture what they noticed. I asked the question, "Where will they tie?" and used a Google form to collect their guesses (see my post on using Google forms to collect student thinking). 

We gave each group only 4 white styrofoam cups. Students were making tables, or writing equations, or some were even wanting to graph their equations. Interesting note: some students started their table with zero cups having a height of 9.2 centimeters. The teacher had only taught graphing systems, so students were already thinking ahead to substitution. It was awesome. She did a wonderful job facilitating her first 3-Act task. We didn’t finish the task in one period, but it felt right knowing we had another half-day to wrap up the task. 

Back to Friday:

After work, I started putting the meat in my upcoming session, Math Mistakes and Error Analysis: Diamonds in the Rough. Although I will be showcasing a couple ways I’ve had success with error analysis with students, I love that I’ll be showcasing some awesome work and contributions from:

• my fellows
• Michael Pershan’s mathmistakes.org,
• Fawn’s Visual Patterns with Michael Fenton’s latest mod
• Open Middle by Robert Kaplinsky and Nanette Johnson

Hope to see you in my upcoming session as we explore why error analysis is important to:

• help drive instruction
• curb student misconceptions and
• strengthen formative assessment. 

Hope your week went well too. If not, hope this week is better.

Rational/Irrational,
516