Building 1/76th of the Great Wall of China

As a teacher this was a wonderful project to watch, the intensity of the student's work, the amazement that turned to tedium in the heat, and then the excitement of finishing, the return of the amazement and the need to show everyone they could find.  

The photographs show our journey of building 1/76th of the Great Wall of China that measured 14,494 centimeters. It started at our classroom, went around the playground, all the way to the second set of soccer bleachers.

 First we had to get blocks, we counted ours, sorted them by color to help with the calculations and set of to ask for more from other teachers.  We got as many as we could.

 

  The students worked in teams to build
sections of the wall, making it curved just  like the photographs of the actual wall they
had previously observed.  It didn't matter to them the exact shape, as they said, it is a representation not a copy.






As we were working, the third grade had spotted us from their window and came out to ask what we were doing. They quickly asked it they could help, "Of course" we said.

 A small group of students recorded the numbers of cubes and the length we had achieved, lots of addition and multiplication going on here.

We took a couple snack and water breaks, this was exhausting work on an unusually hot day, but the students persevered and at last the final blocks were being laid.

The finished wall - a relieved set of builders!

As soon as they were done a cry of "Hooray" went up and everyone fell to the ground!

Within seconds the next cry was, "Can we show everyone?" 

"I'll go to the Middle School."

"I'll get first and second grade"

"Can we show Cat?" Cat is our math specialist.

And they came, virtually the entire school came to visit our wall over the course of the next thirty minutes. The 4th grade led the visitors along the route, shared their experience and answered questions.

What an exhausting but fun day.  I was absolutely amazed at the incredible length the Great Wall of China must be.  At only 1/76 it was an incredible feat of patience and building for the 4th grade, I am glad we only had a limited number of cubes, we'd still be building now!

Inviting the preschoolers to the outside classroom

It is amazing how fear can influence your thoughts.

The children in the Meadow Room emailed our class to ask if they could come down and visit the outside classroom.  They asked if they could play there and look for animals.  When the 4th grade recieved the email their immediate response was a resounding NO!

Their idea of preschoolers, I think from experience with younger siblings was that they wouldn't be able to listen and would potentially destroy the classroom.  The return email was full of rules and regulations.  They basically wrote that they didn't really want them to go, but if they had to, then it was going to be by the 4th graders rules.

Now, the 4th grade have spent a lot of time building their classroom and are already upset that others have been inspired to build spaces or play close by.  They have incredible ownership of their space and are very territorial about it.

So the children of the Meadow Room came over for their pre-visit briefing and a discussion was held.  The 4th grade were very polite and accommodating but I could see that underneath it all they were worried.

We buddied up and started off across the field.  Immediately the 4th graders took charge, waiting at the road until everyine was ready and crossing together. A sense of excitement as in the air as we went behind the ha ha wall.

It was as if the 4th graders had wanted the preschoolers with them the whole time.  They held their hands, led them through the classroom, were very friendly and caring towards them, making sure of their safety with all the big branches.  They then discovered a swinging vine and for the next ten minutes or so took turns to swing. It didn't take long for the 4th graders to take turns with the preschoolers and show them how to swing.  I noticed encouragement for those who were a little nervous of the vine.

Each 4th grader stayed aware of their buddy the whole time.  Many gave their buddies piggy backs on the way back up, and only a few let go off hands.  We decided to extend the moment and eat snack together, it was hard to pull away.






This experience was so magical for both grades.  Once the 4th graders were with the preschoolers they were no longer afraid, they had a better understanding of them. They had been given a chance to share something very special to them and they did it with grace.

And after the visit the resounding response was:
 When can we do this again?

Scale modeling the Great Wall of China.

How long is the Great Wall of China?

A simple question you would think, a quick check on the internet and you have your answer.  Not so.
The Great Wall of China is a series of walls built at different times.  When the children were researching in groups they found all sorts of lengths and answers.  It was wonderful to see them automatically check multiple websites for their answers, and indeed to check with each other.

We got all sorts of answers ranging from 5,500 miles to 13, 000 or so miles.  So what to do?
Well, we decided to settle on the Ming section of the wall which is 5,500 miles or 8,850 km. They are into the Ming dynasty right now from their investigation into the Forbidden City.

Can we build a model?

The first thing I did was to stand back, to let the students figure it out, how would they go about building a model?  One group started building with blocks, their main goal to build an aesthetically pleasing wall that looks like the great wall, complete with watch towers.

Another group decided to use a scale - one cm to one mile in length and then one cm to one foot for the height - this of course ran them into problems.

The idea of scale was there for most of the students but I soon realized that the sense of length was proving to be a difficulty.

So we slowed down.

The next day in math we looked at both standard and metric measurements.  Scales mixing the two measuring units were common and I wanted them to stick with one set of units.  We went with metric and decided on a length scale of 1mm = 1km.  They easily worked out that the wall needed to be 8,850 mm long.   Easy!  I then asked how much space does 8,850 mm take up, is it as long as the trailer?

This proved to be a fascinating glimpse into the students ideas of length and measuring units. As they were studying rulers, it was soon obvious that mm were foreign for many of the students and they explored the idea in detail.

They first looked on rulers to try and find the part that was mm.  They all knew that mm were small but were not sure whether they were part of inches or cm.  We started with that, then moved to how many mm in a cm?  Some said 10, some 11.  It all depends on knowing how to read a ruler.  This led to a great discussion. Then some groups looked into how many mm in a ruler. (standard 12 inch ruler) Next was how many in a meter.  Even though we slowed down, it was amazing quickly the children took themselves step by step to solve the problem.

Think of the math involved, converting mm/cm/m using multiplication and division, the powers of ten.
Reading a ruler, investigating the sense of length and size, making comparisons.

It is one thing to say 8,850 mm = 885 cm or 1 meter 85 cm but it another to really understand how the system works and to get the sense of the scale of the measurement units.

I was so impressed with their enthusiasm and the speed of their understanding.
One group took a long tape measure outside to get a sense of the scale.

So, next:
Will this scale work?  What about the wall height?  With 1mm = 1km, getting the height of only 15 meters is going to be tough.  Let's see what happens.