understanding

They’re not.  What’s bad is when students learn an algorithm – any algorithm from anyone – without making sense of it on their own.

Enter (what is considered by some) the buzz  word: “Strategy” (Guess what, the strategies being taught now are all algorithms).

I often hear teachers talking about teaching students several different strategies for (insert operation here).  Good, right?

Not so much.  Here’s the thing.  If teachers teach all of these different strategies, without student understanding at the forefront, they may as well teach the standard algorithm.  The worst part here is that students can actually be worse off being taught these multiple strategies without understanding than one algorithm without understanding.

Essentially, students are being force-fed strategies (aka algorithms) that they don’t understand and they feel like they need to memorize all of these steps for all of these strategies.  We’re going down the wrong path here.  Our destination was right, but we took a wrong turn somewhere.

It’s time to stop the madness!

Let me tell you a story…

Back in early fall 2007, when I was still a toddler of a math coach, my beautiful wife’s grandmother passed away and the whole family went to her school on the weekend to help her get some lessons together for the few days she would be out.  Truthfully, I was the only one helping since the kids were 7 and 4 at the time.  Kim gave me jobs to do and I did them with precision and efficiency.  One of the tasks she gave me was to make a 18 copies of a few tasks for her students to complete during her absence.

To help her out, I took my son, Connor (the second grader), with me to the copy room so she’d only have 1 child to keep track of while she was trying to work.  When we got to the teacher work room, Connor watched as I placed the small stack of papers on the copy machine tray, typed in the number of copies (18) needed and then hit the copy button.  Within seconds he asked me (in the most exasperated voice he could muster) “How many copies is that going to make?”

I swear, when things like this happen, mathematicians in heaven play harmonious chords on harps using ratios.  I hear them and respond accordingly.  This time, I brought Connor over to the copy machine screen and showed him the numbers.

Me: “Do you see that 5 right there?  That’s how many papers, the copy machine counted, and that 18 right there?  That’s how many copies of each piece of paper I asked the copy machine to make.”

Connor:  “Oh…”

Commercial break:  I didn’t really expect much more than an estimate.  This was September and Connor was a second grader.  He may have heard the word multiplication, but likely didn’t know what it meant.

And we’re back!  His eyes looked up as he thought about this briefly and within seconds of his utterance of “Oh,” he said in a thinking kind of voice, “50…..”

Now, I’m not one to interrupt a student’s thought process – I work with teachers to keep them from doing it.  I actually remember having a mental argument with myself about whether I should ask him a question.  I was so excited in this moment, I couldn’t help myself.  I asked (with as much calm as I could), “Where did you get 50?”

I kid you not, he replied by pulling me over to the screen on the copier and said, “You see that 1 right there (in the 18), that’s a ten. And 5 tens is 50.”

I could hardly contain myself.  Naturally, since I had already interrupted him, I asked what he was going to do next.  I was floored when he said that he didn’t know how to do five eights.  I was floored because he knew how to multiply a 2 digit number, he just lacked the tools to do so.  In the context of this copy machine excursion, Connor made sense of the problem, reasoned quantitatively, showed a good degree of precision, and I’m sure if he had some tools, he would’ve come to a solution within minutes.

As we left the teacher work room, with copies in hand, I asked him to think about it for a bit and see what he could come up with.  When we got back to my wife’s room, I told her all about it.  When I got to the part where he didn’t know how to do five eights, I called across the room to him and asked him if he figured out what five eights was.  As he said, “No.” he paused and thought for a few seconds and said, “Can I do 8 fives?  ‘Cause that’s 40.”  Before I could ask him (thank God), “What about the other 50?”  He said, “40…50…90!”

This second grade boy (My Son!) who had never been taught multiplication, what it means, or any algorithm for it, created a strategy for finding a solution to a contextual problem that most of us would solve using multiplication.  He came up with the strategy.  It was based on his understanding of number and place value and he created it.  These are the strategies students need to use — the ones they develop.

I’ve told this story at least 50 times (I’ve even told it to myself while on the road).  Afterward, I often challenge teachers to take their students to the copy machine and watch this play out for themselves.  Some pushback does come out occasionally with comments like these (my responses follow each):

• That’s because he’s probably gifted.  He is, but that’s not a reason to not do this with any group of kids.  Every student can and will do this when presented with contextual problems and access to familiar tools and where teaching through problem solving is the norm.
• You probably worked with him on multiplication tables.  Yes, and no.  When Kim was pregnant with Connor and on the sonogram table with a full bladder, I leaned close to her stomach and started reciting multiplication facts to make her laugh (I’m cruel for a laugh sometimes) Other than the 4 or 5 facts I quickly rattled off that afternoon, I’ve never recited them since.  I doubt that did much, if anything, for his math achievement.
• You must work with him a lot with math.  Not really!  Other than natural math wonders that have piqued my kids’ interests and sparked some discussion, no.  Questions they’ve had, like – “Dad, how many tickets do you think I have in this Dave & Busters cup?” are all we’ve spent any amount of quality time on.  That and puzzles.

So, when it comes to strategy building, it all has to begin at the student level of understanding.  The best way to do that is to let students develop their own strategies, share them with each other, and build more powerful understanding from there.  Then, if they do get “taught” a standard algorithm somewhere down the road, it has a better chance of making sense.

Math: A Fun After Homework Activity

All week long I’ve been asking Connor, my 9th grade son, what he has been working on in coordinate algebra.  Here’s a snippet of a recent conversation:

• Me:  So, Connor, what have you been working on in your coordinate algebra class?
• Connor:  We’ve been graphing.
• Me:  Graphing what?
• Connor:  Graphing different lines.
• Me:  What kinds of lines are you graphing?
• Connor:  Ummmm…
• Me:  Are they linear functions.
• Connor: Yeah, there are linear functions, but we also do curves…
• Me:  Like what kind of curves?
• Connor: Umm… exponents
• Me:  Ok.  Anything else?
• Connor: Umm…
• Me:  Hey, I want to show you something. . .

Versions of this conversation happened several times this week.  Due to soccer practices, games, homework, and Life in general, we never got much past Connor’s last “Umm…”

Until yesterday!  The conversation changed a bit:

• Connor:  We did something cool in class today.
• Me:  Oh, yeah?  What was it?
• Connor:  We had to build a picture using graphs of different lines.  We built a shamrock.
• Me:  That’s what I’ve been meaning to show you all week.  Go grab my laptop.
• Connor:  (playing game of war on an ipad) But I finished my homework.
• Me:  Just take a look at this for a few minutes and see what you think.
• Connor: (heavy sigh)

Enter Des-Man from Desmos.  Once he had gone through the tutorial, he was hooked. . . for a while!  He engaged in this for about 2 1/2 hours.  When he wanted to make something happen, but didn’t know how, he would come to me and ask.  We’d figure it out together.  The best part of this whole experience was when he realized he knew how to create something on his own and went to his math work from class as a reference.

Fast forward to 2 1/2 hours later, when Connor finished his Desman.

To see the picture in detail along with the equations Connor used to create this graph, click Connor Face Graph.

It didn’t stop there.  I had some tabs open and clicked on one with the In-N-Out Burger task from Robert Kaplinsky.  He was curious enough to work through it even after all of the Des-man work.  So, I showed him more by clicking on the Open Middle tab (also from Robert Kaplinsky).  I selfishly pulled up the task that I wrote in collaboration with Graham Fletcher called The Greatest Difference of Two Rounded Numbers.  After making sense of the problem, and a lot of eye opening moments that led to phrases like “Oh, I can make it larger!” He got what he thought was the final answer and we validated his reasoning by clicking on the answer.  A slight smile!

So, we’re looking at close to 3 hours of after homework math investigation that ranged from rounding numbers to graphing equations, and solving problems.  Sounds like a great evening to me.  Great conversations and fun while learning and reinforcing mathematics understanding!  What could be better?  Talking Math With Your Kids – High School Edition.

Feed the hunger of all ages!

More with Connor:  Real Math Homework and Real Learning

Connecting Percents and Fractions

Not understanding mathematics can be extremely frustrating for students.  As a teacher, figuring out how to help students understand mathematics can be just as frustrating.  My primary go-to resource for these situations is Teaching Student-Centered Mathematics, by John Van de Walle et. al.  because it’s all about focusing on big ideas and helping students make sense of the math they’re learning in a conceptual way.

Recently, I was asked to model a lesson for a 6th grade class who was having difficulty working with percents.  So, I turned to my go-to resource, and during planning, I realized that I didn’t know anything about these students other than that they were struggling with percents.  So, I couldn’t assume anything.  I ended up creating three separate lessons and combined them into 1.

First, I handed groups of students a set of Percent Cards and Circle Graph Cards.  Their task was to match the percent with the corresponding circle graph.  As students were working on this, I heard groups reasoning about how they were matching the cards.  Many started with benchmarks of 25%, 50%, and 75%, while others started with the smallest (10%) and matching it to the graph with the smallest wedge.  As groups finished, they were asked to find pairs, using the matches they made, that totaled 100%.  Once finished, a discussion about their process for completing these tasks revealed a solid understanding of percent as representing a part of a whole.

Now to shake their world up a bit.  I asked them to leave their cards because they would be using them again shortly.  I introduced these Percent circles and asked them what they were.  A brief discussion revealed some misconceptions.  Some students said they were fractions, others said they were wholes because nothing was shaded.  I altered my planned line of questioning to questions that eventually led to a common understanding of what fractions were and how the pictures of the fraction (percent) circles really showed wholes and parts (fractions).

Their next task was to match their cards with the equivalent fraction circle.  This was incredibly eye-opening. Groups began to notice that some percent card matches could fit with multiple fraction circles (50% could be matched with the halves, quarters, eighths, and tenths).   Thirds and eighths were the last to be matched.  But their reasoning didn’t disappoint.  One group noticed that the percents ending in .5 all belonged with the eighths because they were too small to be thirds (the other percents with decimals).

Students were eager to share their thoughts about what they learned about fraction circles and percents:

• Fractions and percents are the same because the pieces look the same.
• 1/4 is the same as 25% and 2/8
• I don’t get why the eighths end in .5.
• The percents all can be fractions.
• 1/8 is 12.5% because it’s half of 25%

Finally, I asked students to solve a percent problem (now that they’ve all realized that fractions and percents can be used interchangeably).   I gave them the m & m problem from this set of percent problem cards.  The only direction I gave was that they had to solve the problem using some representation of the percent in the problem before they wrote any numbers.

My bag of M&M’s had 30 candies inside.  40% of the candies were brown.  How many brown candies is that?

While this was problematic at first, students looked at their fraction circles and percent cards and realized they could use four of the tenths since each tenth was the same as 10%.  Most students needed just one “least helpful” question to get on the right track:  Where do the 30 m & m’s belong in your representation?

Most groups were able to make sense and persevere to solve the problem correctly, and explain why they “shared the 30 m & m’s equally among the ten tenths in the fraction circle” and why they “only looked at four of the tenths because that’s the same as 40%.”

My beliefs that were reinforced with this lesson:

• We can’t assume understanding from correct answers alone.  We need to listen to students reason through problematic situations.
• Students really want to share their thinking when they realize that someone is really interested in hearing it.
• Students crave understanding.  They really want to make sense.
• Procedures are important, but not at the expense of understanding.
• Empowering students by allowing them to build their own understanding and allowing them to make connections allows students to feel comfortable taking risks in problem solving.

Please take a look at Jenise Sexton’s recent blog about percents with 7th grade students for some fantastic ideas about students using number lines and double number lines to solve percent problems.  It’s SWEET!

The Penny Cube

I just finished a 5th grade 3-Act task called Penny Cube that I created last spring.  I tried it then, but just to get some feedback from students and see what I might need to change about how the task should be presented.  Now, after completing this task with two groups of students (at two different points in the year), I’ve learned three things:

1. Students see a video and notice a bunch of things that teachers don’t even realize are there.
2. The curious questions students ask first are often “why” questions.
3. There’s no way to predict everything a group of students might wonder.

I’ll take this reflection from the beginning.  First, I let students know that I was going to show them a video clip.  I also told them that I was going to ask them what they noticed when it was finished playing.  I gave students a chance to brainstorm ideas about what they could do to make sure they would be able to share what they noticed once the clip had finished playing.  Their ideas were amazing:

• We could look for expressions (on faces – I found out later that this student was thinking about context.  A person’s facial expression can tell a lot)  Unfortunately, there were no facial expressions in this video.
• Listen carefully (they might be able to hear something that might give them a clue about what was going on – these students were already expecting a problem situation!)
• Stay focused on the clip.
• Take notes.
• Try to remember as much as you can.

I had never done this before, but after hearing their ideas, I will be using this again.

After showing the video clip for Act 1, I immediately had them talk about what they noticed with their groups.  Then, they were asked to share with the whole group.  Here is what they noticed:

What’s missing from this picture is the wonderful reasoning given for some of these.  For the last bullet, “container is open in the front,” the student told the class that it was open in front so the pennies could be placed in the container more easily (I never thought they’d see or think about that).  They even began to wonder a bit here – “it might be an expression or it might be counting.”  My favorite, though, is the estimation by the girl who said “it looks like 100 pennies in the stack (\$1.00).”  This was particularly interesting to me because of what happened when they were asked to estimate for the focus question.

The wonders were typical from what I usually get from students new to 3-Act tasks, but I handled it a bit differently this time.  Here are their wonders (click here for a typed version of Penny Cube Notices&Wonders):

In my limited (yet growing) experience with teaching using 3-Act tasks, I’ve noticed that the wonders are initially “why” questions (as stated in number 2 above).  I told the class that I noticed that the questions they were asking were mostly “why” questions.  I asked them what other words could be used to begin questions.  Rather than trying to steer students to a particular question, I decided to focus the students’ attention on the kinds of questions they were already asking, and guide them to other types of questions.  It didn’t take long!  Within about 5 minutes, students had gone from “why” questions to “how many . . .” and “how much . . .” questions which are much easier to answer mathematically.

The students were then asked to figure out what they needed to solve the problem.  From experience with this task, I knew that most students would want pennies, so I had some ready.  I didn’t give them the Coin Specifications sheet, because no one asked for it.  I did have it ready, just in case.  Every group asked for pennies and rulers.  I wasn’t sure how they would use them, but I was pleasantly surprised.

Here’s what they did:

How many pennies in 2 inches

How many pennies in an inch

How many pennies fit on a 6 inch edge of the base

How many pennies cover base

How many stacked pennies in 2 inches?

The students all started in a place that made sense to them.  Some wanted to figure out how many in the stack, so they stacked pennies and quickly realized (as I did when filling the cube) that you can’t stack pennies very high before they start to wobble and fall.  So, they measured smaller stacks and used that info to solve the problem.  Others wanted to find number of pennies along an edge to find how many cover the base, then work on the stacks.  Students were thoroughly engaged.

After three 1 hour classes, students were wrapping up their solutions.  Some groups were still grappling with the number of pennies in a stack.  Others were finished.  A few were unsure about what to do with some of the numbers they generated.  All of this told the classroom teacher and me that there were some misconceptions out there that needed to be addressed.  Many of the misconceptions had to do with students disengaging from the context, rather than integrating their numbers into the context:

• One group was unsure of whether to multiply  the number of pennies in a stack by 12 (6 inches + 6 inches) or to use 64.
• Another group found the number of pennies to cover the base and multiplied it by itself to get their solution.
• A third group found 37 pennies in 2 1/2 inches and was having a difficult time handling that information.
• A fourth group had come up with two different solutions and both thought they were correct.  Only one could defend her solution.

Eventually, several groups arrived a solution that made sense to them.

Time to share!

I chose one group to share.  This group had a reasonable solution, but their method and numbers were different from many of the other groups, so this is where we were hoping for some light bulbs to begin to glow a bit.

This group shared their work:

I asked the class what they liked about the work.  The responses:

• The math (computations) are written neatly and they’re easy to follow.
• I know what their answer is because it has a bubble around it.
• The question is on it.
• It’s colorful.

All good.  Now, for the best part:

What questions do you have for this group?  The responses:

• Where did you get 34?
• What does the 102 mean?

Any suggestions for this group to help them clarify their work to answer some of your questions?

• Maybe they could label their numbers so we know what the numbers mean.
• Maybe they could tell what the answer means too.  Like put it in a sentence so it says something like “6,528 pennies will fit in the container.”
• Maybe they could have a diagram to show how they got a number like 64 or 34.  I know that would help me (this student had a diagram on his work and thought it was useful).

The light bulbs really started to glow as students began making suggestions.  As soon as a suggestion was made, students began to check their own work to see if it was on their work.  If it wasn’t, they added it.  All of the suggestions were written on the board so they could modify their work one final time.  The best part about this whole exchange was that students were suggesting to their peers to be more precise in their mathematics (SMP 6 – Attend to precision).  And, they really wanted to know what 34 was because they didn’t have that number on their boards (which is why I chose this group).

Now for the reveal!  When I asked the class if they wanted to know how many pennies were in the cube, they were surprised when I pulled up the reveal the video.  I guess they thought I’d just tell them (that’s so 1980’s).  They watched to see how close they were and when the total came up on the screen, many cheered because they were so close!

The students in this class were engaged in multiple content standards over the course of 3 days.  They reasoned, critiqued, made sense, and persevered.  It’s almost difficult to believe that this class was a “remedial” class!

Below, I’ve included a picture of each group’s final work.

Finally, one of the conversations witnessed in a group was between a girl and a boy and should have been caught on video, but wasn’t.  This group had an incorrect solution, but they were convinced they were correct, so to keep them thinking about the problem, I asked them how many dollars would be equal to the number of pennies in their answer (3,616).

• Girl:  There are 100 pennies in a dollar.  So 600 pennies is . . .
• Boy in group: \$6.00
• Girl (after a long pause):  1,000 pennies equals \$10.00
• Boy:  So that’s . . . um. . .
• Girl:  We have 3,000 pennies, so that’s \$30.00.
• Boy:  \$36.00
• Me:  Share with your group how you know it’s \$36.00
• Boy:  Because \$30.00 and \$6.00 is \$36.00
• Girl:  And the rest (16) are cents.  \$36.16!

And they didn’t even need a calculator!

Math really does make sense!

How Old is The Shepherd? Revisited in 3rd Grade

Over the past few weeks, I’ve shown the How old is the shepherd? problem to both of my kids and then shown them the video  from Robert Kaplinsky’s blog. Both were shocked at how many students don’t pay attention to what is happening in the problem.  Connor even said, “I guess I’m not one of the 24.”

Here is my son, Connor, with his response to the problem:

Unfortunately, his first statement, “That’s stupid!” was not caught on video!

My daughter, Lura, with her response:

Last Saturday, after ambushing one of my daughter’s friends with the problem while she was visiting, Kim (my wife) became more curious about the problem, so I showed the video to her and shared some of the data on Kaplinsky’s blog. She was also shocked at the results.  We had a brief conversation that went something like this:

Me: This is why we need to teach math content through patient problem solving and sense making!

Kim: Ok. (with a look that says, I know you’re passionate about this, and that it’s important. We’ll talk later. Go make a 3-act video and post it to your blog.)

Me: Ok.

It was left alone until this morning. It’s just me, but I like to think we would’ve talked sooner if I hadn’t been fighting a cold. She texted me and asked me to send her the Shepherd problem. I did, but only with the requirement that she share what she does with it.

Kim (and her co-teacher) gave the problem to each of their students and I just received the results:

• 3 out of 19 students made sense of the problem (15.8%)
• One student added 125 five times.
• One student reasoned that by the time you had 5 dogs and 125 sheep, you have to be in your fifties.
• One student divided 125 by 5.
• 6 students added 125 and 5 to get 130.
• 3 computed an operation with the two numbers incorrectly
• The other students guessed or showed no reasoning.

Now the good stuff:

• One student (an autistic child) shared his reasoning about the problem with his classmates:

“The shepherd has no-o-o-othing (said as a sheep might say it) to do with the sheep and the dogs.”

• Both teachers lost it!

Take aways from this:

• It’s best that we start teaching math content through problem solving early and consistently K-12 and beyond.
• Making sense of mathematics needs to be a priority for all students. (SMP 1)
• All students bring something of value to a classroom.
• Stories like the student who shared his reasoning sometimes get us through days that are not so much like this.

Below, you will find some of the students’ reasoning.

How old is the shepherd_

It seems like a silly question, really.  The answer, we would expect, is “Yes, every day!” Unfortunately, I’m not sure this is the case.

For those of you about to first step foot on the exhilarating math train that is teaching mathematics, it’s probably a good idea to share a few facts and myths about learning and doing mathematics.

Myths:

• math is equated to certainty (sadly, this belief is held by many!)
• knowing mathematics means being able to get the correct answer – quickly (again, this belief is held by many)
• mathematical correctness is determined through the use of a teacher or an answer key.

Facts:

• mathematics  is a science of pattern and order (this was taken from Everybody Counts)
• math makes sense (teachers cannot make sense of mathematics for students)
• doing mathematics requires students to solve problems, reason, share ideas and strategies, question, model, look for patterns and structure, and yes even fail from time to time.

If you walk into a math classroom – at any level – students are doing mathematics if you see/ hear students doing the following:

 Explore Construct Justify Develop Investigate Verify Represent Describe Conjecture Explain Formulate Use Solve Predict Discover Discuss

If teachers are doing most of these, a shift needs to happen.  All students can do these things.  All students can learn and do mathematics.  All students can make sense of mathematics because math makes sense.

As I reread what I’ve written so far, it tends to read a bit negative.  That was not my intent.  I just wanted to point out that wherever you are in the vast range of stakeholders of math education, please be aware that just because there are students in a math class, does not mean they are necessarily doing mathematics.  That wasn’t much better!

This might be a better way to end this post:

There are many of us (more than I thought when I first started this blog) who are making the case for teaching mathematics for understanding through engaging tasks.  Dan Meyer, Andrew Stadel, Fawn Nguyen, Graham Fletcher, Jenise Sexton, and Robert Kaplinsky, just to name a few, use their blogs to share their thoughts, lessons & tasks they create, and their thoughts on what it means for students to learn and do mathematics.  These, and many others, continue to push all of us to become a better math teachers.  Personally, they strengthen my resolve, knowing that our numbers are growing along with our minds and the minds of our students!

Moving Decimals!?!?!?

Why are there teachers out there still teaching multiplication (and division) with decimals where the decimal is moving?

The answer to this question is simple.  It’s easy.  It doesn’t take as long to teach (though when you look at all of the time spent on remediation, I tend to disagree here).  And it takes little preparation.

Let’s take a look at this.  First:  It’s easy for teachers.  It is!  I agree.  If the teacher has this procedural understanding down, all they need is to find a set of computations (usually in the form of a worksheet with no context) Unfortunately, this procedural understanding breeds more procedural understanding and neglects the sense making necessary in learning mathematics.  Teaching  any mathematical procedures at the expense of making sense is like teaching only phonics with no connection to literature and comprehension.

By teaching moving the decimal, teachers are undoing any understanding of place value (and this is often surface understanding).  Think about it.  In first grade, students learn that when you get too many (10) popsicle sticks they need to get grouped together to make one ten.  This requires sense making on the students’ part.  The students are beginning to think of the group of ten as a unit.  The “ten” is a unit and they can work with that unit in much the same way as they work with a “one.”  In terms of place value understanding, the physical grouping and the representation on a place value chart help students make the connection between the digits and the values of those digits due the quantities of popsicle sticks (or any other material).  The digits are moved to a different place value based on the quantity.  Quantities connected to groupings connected to place value.  It makes sense to students when they experience it consistently.

• Two popsicle sticks are represented by a digit 2 on a place value chart
• When we get to 20 popsicle sticks (10 times as much as 2), that digit 2 that was in the ones place is now moved to the tens place.  The digits are placed based on the quantity they represent.

Flash forward to 5th grade (for example).  A student is learning to multiply decimals and the teacher is teaching procedural methods where students are told to move the decimal.  What if the student gets the incorrect product?  Do they know?  Are they aware that their computation is off?  Most likely not.  They have been taught to follow procedures (often blindly) and if they do, they’ll get the correct product.  So, when they do make an error, they are not concerned, because they’re being taught to be robots.  Follow these steps and you’ll get the right answer.  Here’s how it might sound in a classroom:

Problem on the board:  10.030 x 0.03

Teacher to student:  You made a mistake.

Student:  (answer 0.03009) But I followed the steps.

Student:  Ok. (after a few minutes) I got the same thing.  I checked my steps.

Teacher:  Did you check your multiplication?  Maybe your error is in the facts.

Student:  Yes.  I checked the multiplication – all of my facts were correct.  I don’t know what I did wrong.

Teacher:  Let me see. (a few minutes pass) Right here.  Your decimal is in the wrong place.

Student:  But I counted the places and counted back.  Why did I get the wrong answer?