Strategy Development

About Strategy Development (and Algorithms)

So there’s this thing going around about algorithms being a bad.

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.

arrrgh

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!

How?  you ask.

Let me tell you a story…

Storytime_logo

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.

 

 

 

 

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.

Teacher:  You made a mistake.  Please check your work.

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?

Teacher:  The answer is 0.3009.

Student:  But if you count the decimal places, the decimal should go 5 places back, not 4.

Teacher:  Hmm?  Thank you for bringing this to my attention.  I’ll take a look at it. . .

This scenario is very informative.   First, it’s obvious that no one in this situation “owns the math.”  The teacher is trying to be the owner, and in the student’s mind, it may be the case – as soon as the teacher says, “let me see.”  The student is trying to make sense (once the teacher corrects him), but can’t and doesn’t even know where to begin, due to the limiting procedural understanding in place.  Based on the “rules” the student learned, he is correct. So why is the answer incorrect?

One thing that the teacher did well is admit that he doesn’t know and that he wants to try to make sense of the situation, but that’s really just the beginning.  Students should also make sense of why the rule fails here.  Instead of blindly following rules, students should be estimating and using what they know to make sense (about 10 x 0.03 = 0.3 so my answer should be really close to 3 tenths).  This should be a part of every student’s math day.  It can’t just be told to students.  They need to experience the value of estimation through problem solving situations on a daily basis.  Over time, students adopt this valuable strategy and use it readily in multiple situations.

Learning (and teaching) mathematics is about making sense, not just procedures. There’s no better time to start than the present!

A Number Talks Reflection – A Look Back Over the Past 3 Years. . .
 Before reading this post, you may want to check out the GloSS and IKAN diagnostic math assessments from nzmaths at this website:   http://www.nzmaths.co.nz/mathematics-assessment.  These assessments are diagnostic interviews that teachers use with students.  When students respond with answers to the problems posed by the teacher, the teachers have to listen to students’ reasoning, not just the answer.  The information gathered is incredibly powerful and has driven our teachers to ask for resources and strategies that will help their students grow and progress through these developmental stages.

I introduced number talks to my school during pre-planning three years ago.  I read the book the previous summer and knew it would be a success if I could just get my teachers to try it.  The challenge for me was to find a reason for them to want to try this new thing called number talks in the midst of all of the other new initiatives.  I looked at what we had been doing over the past year and a half and tried to find where these number talks would fill a need.  When I discovered that need, several (more than I expected) teachers wanted me to introduce number talks with their classes immediately – during the first week of school!

 

The need I found was to improve strategies for computation to help students achieve higher strategy stages on the GloSS assessment.  Teachers had noticed that students were getting stuck on stage 4 (basically, the majority of students – even those in 5th grade – had one strategy for everything, counting on).  They were stuck because we continued to assess, but hadn’t looked at the data gathered from those assessments to come up with a course of action to help students.  The ideas were out there and we had discussed strategies before, but few teachers were implementing these ideas daily.  We wanted the pig to grow, but we were weighing it instead of feeding it!

 

When I started introducing the number talks, teachers were very interested and many were excited about out how this would work.  I worked with each teacher/class for an entire week.  For four days, I would model the number talks.  On the fifth day, the classroom teacher would take over and I would observe.  We would meet after to talk about the experience and we would discuss how the teacher would move forward from this point.  Sometimes these were difficult conversations.  What I learned from these discussions was that many teachers thought of this as a magic bullet, where teachers would talk about strategies first and then have students practice a few verbally.  This myth was dispelled as soon as I walked into the first classroom.

 

I introduced number talks to every class that year.  Some teachers wanted to see them, and then decide whether to use them.  Some knew they wanted to use them, and some just wanted 4 days with someone else teaching for 20 minutes.  And there was one skeptic, who did number talks with the expectation that they would not work.  And that was ok.  It wasn’t mandatory, just a strategy.  A tool to use to help kids help themselves.

Number Talks Assessment from 3rd grade with teacher commentary (September)

Number Talks Assessment from 3rd grade with teacher commentary (September)

I would check up on teachers every so often to see how teachers and students were doing with their number talks.  Some had stopped doing them after a while, some only did them 3-4 days a week, but there were some… Some who saw the value right away and did them religiously (I apologize for this blatant disregard of separation of church and state) every day.  These teachers took number talks and ran with them!  They not only used them to help students develop strategies, they used them to assess those strategies. They were asked to share. And they did.  During professional learning, faculty meetings, and through emails, other teachers began to notice that the number talks were beginning to show results.

 

Teachers were amazed, and so was I, when one month after introducing number talks to a third grade class, I walked in just to see what was happening and saw student after student mentally adding two three digit numbers using strategies based on place value, friendly numbers, and compensation.  These were a mixture of Special Ed., EIP, Title, and Gifted students.  They were all at different places in their understandings of the strategies they were hearing and using, but because they were developing the strategies, they were empowered to keep trying to use them and develop new strategies that were efficient (quick, easy to think about, and work every time).

 

The teachers who did the number talks consistently and with fidelity were the ones whose students reaped the rewards.  When the teachers assessed with the GloSS at the end of the year, those teachers were the ones tracking me down to tell me their stories.  I heard things like:

 

“All but two of my students went up 2 strategy stages.  The others went up 1.  It has to be the number talks.  That’s the only thing that really changed this year.”

 

“Number talks was a great way to really listen to my students and hear what they know.  The GloSS makes more sense now.”

 

“I can’t believe what my lower students said during the last GloSS assessment.  They really used what we did in those number talks.”

 

“Number talks really helped my kids with their strategies, and it shows in their other math work.  I love number talks!”

 

Number talks have been a huge success for all teachers at my school who have used them with fidelity.  We’ve hired some new teachers this year and they seem just as eager to learn about number talks as the teachers I worked with a few years ago.  Now, with all of this experience and several number talks experts, our school can offer more support than ever to these new teachers.  We’re all expecting the best.

 

Oh, and remember the skeptic. . . well, she’s one of the experts now!