So while we were out walking a mile around the school, I noticed the kindergartners picking up trash on the school grounds. We waved to them, they waved back, we continued our walk, and they continued to collect garbage and put it in the large trash bags their teachers had brought outside. I ran into one of their teachers at the end of the day.

"Great job! It looks a lot better out there," I told her.

"We collected 37 pounds of trash!" she told me excitedly.

Trying to make math meaningful in an elementary school somewhere off the New Jersey Turnpike.

## Wednesday, April 30, 2014

## Thursday, April 24, 2014

### Our First Real 3-Act

We tried our first real 3-Act on Monday with Jeff's fourth graders. Motivated by issues of perimeter and scale (which I blogged about here), and a great post by Matt Jones over at The Math Lab @ Rm 27, we started out with this photo:

Lots of excitement! First we asked the kids if they knew what they were looking at. We were surprised that so many of them knew right away that it was a photo of our school. In order to orient them, we identified some features together and marked up the photo on the smart board:

Those scale-related issues had led us to Andrew's estimation180 series on flight distances, which in turn led us to wonder: Do the kids even

After discussing individual too lows, too highs, and just rights, the class agreed that the answer would lie somewhere between 1/2 times around and 9 times around.

Then it came time for...

They liked this, but soon realized that they needed to know how many feet were in a mile. No one had this answer, though there were some guesses, including 12 and 100. We had them find the answer in the measurement table in the back of their journal.

After we established that there were 5,280 feet = 1 mile, we set them off to work.

The kids needed a bit of help with that...

This is how the class determined that they would need to walk two Halloween parade routes plus most of a third. We approximated the stopping point along the driveway entrance to the school.

And that would have been the end of that, except...

Lots of excitement! First we asked the kids if they knew what they were looking at. We were surprised that so many of them knew right away that it was a photo of our school. In order to orient them, we identified some features together and marked up the photo on the smart board:

Those scale-related issues had led us to Andrew's estimation180 series on flight distances, which in turn led us to wonder: Do the kids even

**know**what a mile looks like? Could we relate that to the perimeter of the school grounds? Our school does a Halloween parade every year so...**ACT ONE:****How many Halloween parade routes would you need to walk to go a mile?**

The red line indicates the parade route and also defines the perimeter of the grounds (not including the parking lot and the large field.) |

After discussing individual too lows, too highs, and just rights, the class agreed that the answer would lie somewhere between 1/2 times around and 9 times around.

Although each student is responsible for their own personal number line in their math notebooks, we also like to have a class number line as well. |

Then it came time for...

**ACT TWO:****What do you need in order to figure this out?**

Some representative responses:

- "How long is a mile?"
- "How long is half the parade route in kilometers?"
- "I want a long tape measure that I could stretch around the school."
- "I would need a meter stick."

- "What is the perimeter of the school?"
- "How long are the sides?"
- "How many feet/inches/yards in a mile?"

The measurements are approximate. |

They liked this, but soon realized that they needed to know how many feet were in a mile. No one had this answer, though there were some guesses, including 12 and 100. We had them find the answer in the measurement table in the back of their journal.

There's quite a bit of information back there, and it wasn't easy for them to locate. |

After we established that there were 5,280 feet = 1 mile, we set them off to work.

**ACT 3**

**Figure it out!**

We liked that the computation was just the means to an end, not an end in itself. And it turns out that twice around is still not a mile, but three times is more than a mile. Hmmm. |

We needed to break the side where the parade starts into two separate segments and add on lengths from there until we got close to 5,280 feet. |

And that would have been the end of that, except...

**ACT 4****How long does it take to walk a mile?**

We couldn't resist. Here was a perfect opportunity to build a personal referent for 1 mile, based on something that each child knew well: the route of the Halloween parade. And since we are now programmed to think of most of our tasks as estimation180-type activities, we had to make number lines for our too lows, too highs, and just rights.

Ultimately the class was satisfied that it would take us somewhere between 1 minute and 2 hours to walk a mile. And then we all went outside and walked a mile, almost three Halloween parade routes, as Jeff and one of his students kept track of the time. It took about 20 minutes.

We collected the kids on the grass under a tree. "What does a mile feel like?" I asked.

As the discussion wrapped up, one student gazed over at the large soccer field across the entrance driveway.

"I wonder how long it would be around

Funny you should ask...

Ultimately the class was satisfied that it would take us somewhere between 1 minute and 2 hours to walk a mile. And then we all went outside and walked a mile, almost three Halloween parade routes, as Jeff and one of his students kept track of the time. It took about 20 minutes.

We collected the kids on the grass under a tree. "What does a mile feel like?" I asked.

- "A mile doesn't feel like a lot."
- "A mile feels like exercise."
- "It was easy."
- "It wasn't as far as I thought."
- "A mile is tiring."
- "A mile makes me feel hungry."

As the discussion wrapped up, one student gazed over at the large soccer field across the entrance driveway.

"I wonder how long it would be around

**that**big field?"Funny you should ask...

## Wednesday, April 16, 2014

### Pie-Eating Contest

Sandwiched between a unit on long division and a unit on perimeter and area, our fourth grade curriculum called for a very quick unit on angles. As it does quite often, inspiration came from Andrew Stadel's estimation180 site; in particular the activities for days 112, 113, and 114. Relating angles to pieces of pie led me to adapt the Everyday Math game Angle Race into a "pie-eating contest" for our fourth graders.

After looking at their completed pies, I had another idea. Cut out the slices and classify them as acute, obtuse, right, or straight.

I had some other ideas that I did not get to try out:

An example of each. |

After looking at their completed pies, I had another idea. Cut out the slices and classify them as acute, obtuse, right, or straight.

Jeff and I thought it would be a good idea to let them combine angles. Here two 15 degree angles and a 150 degree angle have been combined to make 180 degree angle. |

Three 30 degree angles make one right angle. |

All done! |

I had some other ideas that I did not get to try out:

- Have partners cut out their slices, mix them up, and then reassemble the pies like a puzzle.

I tried this out. This was not the original configuration. |

- Play a game where the pieces get all mixed up. Players take turns pulling out a piece at random. Larger piece (or smaller piece) wins, and player gets points equal to difference in size.

## Wednesday, April 9, 2014

### The Gift That Keeps Giving

Andrew Stadel's estimation180 continues to inspire us. The seemingly simple idea continues to amaze as it takes us into uncharted waters of number sense, measurement, computation, and now, quite unintentionally, scale.

This last go-round started with something that occurred to me at home, watching my daughter get a snack.

My idea was to just throw it up there, with no review of perimeter or mention of what units to use. I was curious to see what would happen. Within a few seconds several hands shot up:

So a quick review. Then:

I was relieved that at least they were all linear measures, but clearly we needed work on choosing appropriate units. After looking at a meter stick, and a 12 inch ruler, we narrowed it down to centimeters or inches, and I told them we were going to use inches as our unit.

They made their number lines, with their too low and too high boundaries, and just right estimates. Then I showed them the reveal:

There were cheers, groans, sighs, and audible expressions of puzzlement. It was clear we had some work to do, and here's what arose from the class discussion:

Day 2:

After discussing some too lows and too highs, a girl in the back volunteered her "just right" at 4 inches. When asked why, she explained that she drew the wheat thin in her notebook, and figured each side to be 1 inch long. She was close:

I loved that the girl had drawn a picture of the wheat thin in her notebook, and we all took a look.

Day 3:

Working with the idea from the previous day, I asked the kids to draw out a diagram of the Club Cracker and estimate the side lengths. After a few minutes, I asked for some perimeter estimates, and was surprised to hear a response of 5 inches, which was the answer from the previous day. I wondered how, given the visual, a student could come up with the same perimeter for both crackers. A quick look at her book revealed how: She had drawn a picture of the cracker and measured the sides of the picture!

Clearly there was some confusion. Is it possible that in the student's mind there are actually

Day 4:

I liked this one because it was a triangle, and provided another opportunity to add mixed numbers.

Day 5 was another hamantash, this one a little larger. Which led us into...

Day 6:

Again, we talked about scale (on the smartboard, the side lengths measured around 22 inches), and the importance of using the wheat thin (the side lengths of which had already been established) as a "ruler".

We then proceeded to finish off the perimeter series with three whiteboards: a 12" x 9" student whiteboard, a larger one attached to an easel, and finally one mounted on a classroom wall.

So in addition to building number sense, we had also touched on perimeter, adding mixed numbers, selecting appropriate units, measurement equivalencies, scale, and classifying two dimensional shapes. What I loved about it all was that the concepts arose naturally from the activity. As we move into a unit on perimeter (and area) in a few weeks, I am curious to know what effect this will have on their understanding. I am becoming more convinced that we can pre-teach, preview, re-teach, and reinforce many skills and concepts in very meaningful ways by embedding them within these estimation activities.

This last go-round started with something that occurred to me at home, watching my daughter get a snack.

My idea was to just throw it up there, with no review of perimeter or mention of what units to use. I was curious to see what would happen. Within a few seconds several hands shot up:

**Students**: What's perimeter again?So a quick review. Then:

**Students**: What units should we use?**Me:**What do you guys think would be good?**Students:**Feet! Inches! Centimeters! Meters!I was relieved that at least they were all linear measures, but clearly we needed work on choosing appropriate units. After looking at a meter stick, and a 12 inch ruler, we narrowed it down to centimeters or inches, and I told them we were going to use inches as our unit.

They made their number lines, with their too low and too high boundaries, and just right estimates. Then I showed them the reveal:

They were going to have to work for the answer. |

- We would need to use the cracker's shape to infer the other side lengths.
- The cracker was rectangular, which meant that opposite sides were equal in length.
- The two little marks after the numbers meant "inches".
- The lengths of each side would have to be added to find the perimeter.
- It was a chocolate graham cracker.

After various number models, from 5 + 5 + 2 + 2, to 10 + 4, to (2 x 5) + (2 x 2), to 7 + 7 were vetted, and the perimeter was established at 14 inches, I showed the kids this demonstration under the document camera:

The graham cracker framed by anglelegs. They now represent the cracker's sides. |

The four sides laid end to end. I hoped that this visual would reinforce the idea of perimeter as the total length of the sides. |

Day 2:

After discussing some too lows and too highs, a girl in the back volunteered her "just right" at 4 inches. When asked why, she explained that she drew the wheat thin in her notebook, and figured each side to be 1 inch long. She was close:

By providing the measure of only one side, I wanted them to infer that it was a square. I also wanted them to practice adding fractions. |

Notice that her too high is 14 in, which was the perimeter of the graham cracker. |

What's the perimeter of the Club Cracker? |

Working with the idea from the previous day, I asked the kids to draw out a diagram of the Club Cracker and estimate the side lengths. After a few minutes, I asked for some perimeter estimates, and was surprised to hear a response of 5 inches, which was the answer from the previous day. I wondered how, given the visual, a student could come up with the same perimeter for both crackers. A quick look at her book revealed how: She had drawn a picture of the cracker and measured the sides of the picture!

Clearly there was some confusion. Is it possible that in the student's mind there are actually

**three**crackers: the actual cracker, the picture of the cracker on the smartboard, and the picture of the cracker drawn in their notebooks? Hmmm. So this is what led us to a discussion about**scale.**Another opportunity to add mixed numbers. |

What's the perimeter of the hamantash? |

This also led to a discussion about how to classify the triangle based on its side lengths. |

Here's an example of student's notebook. This was an excellent estimate, only 1/2 inch off! |

Day 6:

What is the perimeter of the matzo? |

Again, we talked about scale (on the smartboard, the side lengths measured around 22 inches), and the importance of using the wheat thin (the side lengths of which had already been established) as a "ruler".

Another example of a student's work. |

We then proceeded to finish off the perimeter series with three whiteboards: a 12" x 9" student whiteboard, a larger one attached to an easel, and finally one mounted on a classroom wall.

So in addition to building number sense, we had also touched on perimeter, adding mixed numbers, selecting appropriate units, measurement equivalencies, scale, and classifying two dimensional shapes. What I loved about it all was that the concepts arose naturally from the activity. As we move into a unit on perimeter (and area) in a few weeks, I am curious to know what effect this will have on their understanding. I am becoming more convinced that we can pre-teach, preview, re-teach, and reinforce many skills and concepts in very meaningful ways by embedding them within these estimation activities.

## Tuesday, April 1, 2014

### Trying to Make Some Sense Out of Long Division

I was inspired by Nicora Placa's post on tape diagrams. It seemed like a natural fit, because the kids were already comfortable using the diagrams to solve "fraction of"problems, which I've blogged about here. I envisioned the move from a partial quotients algorithm to a traditional algorithm unfolding in phases. So we start with a division problem:

**Phase 1**: Model with a horizontal tape diagram:

We did some guided practice,then it was on to...

**Phase 2:**Model with a vertical tape diagram:

More guided practice:

**Phase 3**: Let's get more symbolic:

We told the kids to "draw the rest of the box". Now the tableau makes sense. The division bracket is just what's left of the vertical box that houses the dividend. |

**Phase 4:**Traditional algorithm

Here's what's changed: We remove most of the horizontal box. Instead of writing the quotient as 30 + 9, we record it as a 3 in the tens place and a 9 in the ones place. |

This was the page you received if you still liked to draw the tape diagram... |

...and this one was for the kids who had moved to the next stage. |

This was for the kids comfortable with the traditional long division algorithm. |

11 kids used the horizontal tape diagram with the divisor boxes and partial quotients (phase 2)

4 kids used the horizontal tape diagram without the divisor boxes & with partial quotients (phase 3)

18 kids used the traditional long division algorithm

4 kids used alternative methods from home

Not all of it was completely accurate, but Shannon, Jeff, and I all agree that we are

**much**farther along with getting them all comfortable with the traditional division algorithm than we have ever been before.

Here's what I liked about using tape diagrams:

- The traditional long division tableau now makes sense because it comes from somewhere.
- Beginning with a tape diagram reinforces the notion of division as equal sharing.
- Not necessary to remember an acronym "DMBS" (divide, multiply, subtract, bring down).

Here are some issues:

- The tape diagram does not reinforce the notion of division as equal grouping. We thought quite a bit about that. But we felt that since the diagram was going to lead into the traditional algorithm, and that was what would be used to solve division problems, we would need to set that aside.
- The diagram gets more problematic for larger dividends, but that is what drives the need for the algorithm.

For our first time through, I think I'm pretty happy. Thoughts and suggestions are encouraged and appreciated!

Subscribe to:
Posts (Atom)