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Models and Learning by Doing or How Design Failures Can Teach the Best Lessons

Today, I and a couple of volunteers went into the 2nd grade classroom and had the students build models of satellites.   The students have already had "changes of state" lessons in which they learn about solids, liquids and gasses.  Building off of that, I use the activity from teachengineering called Beat the Heat.
In this activity, I talk to the students about models.  We talk about how you can build a model car out of legos, or build a model airplane.  It is not the same as the real thing, but that you can build and test aspects of the design.  Today, we used plastic eggs as a model for the shell of a satellite that we want to send to Venus.  Venus is a hot planet reaching temperatures of 1,300 degrees Fahrenheit.  We talk about what kinds of things you would want to learn about Venus, so we decide a camera is one of the most important things you would want in your satellite.  Instead of using a camera in our test, we use butter.  The idea is to give the students a pat of butter and have them protect it from heat.  We also give the students various materials to use such as tooth picks, cloth, packing peanuts, cotton balls, balsa wood.

The students then design and build their satellite model using these materials.  

Next, they draw and label their designs.

Finally, I use box fitted it with a hole for a hair dryer for a heat source, with a thermometer and a viewing window with egg cartons in the bottom for holding eggs.  I then turn on the hair dryer and heat the box to 160 degrees F.   This is our Venus simulator or testing rig.

After the temperature in the box reaches 160 degrees F, we take apart the eggs and look at the results.

We learn that if the butter is kept away from the surface of the eggs, it generally survives, but if it is in contact with the egg, it will melt.

In the second of the six classes I ran this exercise with today I had one group whose butter completely melted.  The group was pretty dejected, but one of the other students spoke up and said,

" Don't worry.  Ms. Skalak told me last year that failing was a learning experience.  Last year when we built water filters I ended up with sand all in my water.  But, now I know better how to design the filter."

I asked the student if he remembered it more because it didn't work out as he had hoped, and he said yes.

Learning by doing is a great way to get the students to learn a concept not just with their head, but with their whole being.  I think this student learned many lessons last year:

•  he will never put sand in a water filter without something to hold the sand in the filter such as cloth or screen
• the failure of his design was a bit painful at the time, but it is something that engineers have happen all the time
• it is okay to fail, because it gives you an opportunity to learn and make it better

Are the students going to run out and build a satellite for NASA based on these ideas?  Of course not, but if they can learn something like this student did about failure, and the opportunity to learn something from the failure.   I think the exercise is more than worth it in time and effort, and besides, it is just fun to do.

Building an Egg Racer and an Interest in Engineering

I teach an after school class at our local school which the people who run it call "Eggineering".  In this class, well, I call it a class, but really it is an after school program that extends learning without being too school-like.  I have 5 one hour session in which I have fourth and fifth graders build a car I call an Egg Racer.  This idea was taken from another school which has all of their fifth graders build the car.

I don't have any photographs today, but will take some next week, but I thought I would share the initial write-up and the lesson on engineering drawing.

Last year I spent an hour working with the students on the engineering design process, but had a difficult time getting them to follow the process.  So this year, I decided I would concentrate on teaching them to draw their ideas, and the requirements, and then just let them go build.

Here is the writeup.

Eggineering:  Designing an Egg Racer

Team Members:         _________________________________

                                    _________________________________

                                    _________________________________

                                    _________________________________

Design Brief:  Your team has been assigned to design and build a fast, convertible sports car.  This car should allow a driver, an uncooked egg, to “drive” down a track going down the track and across the floor as far as possible.  In addition, the driver must survive a crash test on 6 foot track, crashing into a barrier.

Design Requirements: 

·      You will use parts from given design kit.

·      Car must not be wider than 12 ½ cm, including wheels and axles.

·      The car must not be longer than 24 cm.

·      The car must be open topped ( nothing above the egg’s head).

·      The total weight of the car and egg must be less than 10 ounces.

·      The car must include at least one of the following safety devices: seat belt, air bag, and/or rollbar/cage.

·      The egg’s face (a circle one inch in diameter – use a quarter) must not be covered so he can see the road. 

·      The egg may wear a safety helmet.

·      The egg must be able to get out of the car easily so he can be inspected for injury after the crash test.

Design Criteria:  Your team’s car will be judged on the following items:

·      Operation of the car, how far it moves down the track and how well it protects its passenger

·      Elegance of design and your engineering drawing

·      Use of available resources

·      Reliability (how consistently your car performs)

·      Ease of use (how easily your egg can be put in and taken out of the car)

Eggineering:  Designing an Egg Racer

Evaluation Guidelines

Judgment Criteria	Maximum Points	Score
Track Performance (1 point for each foot of travel beyond the track)	15
Crash Test Performance (10: no cracks; 5: minor cracks; 1 major cracks; 0: completely smashed)	10
Repeatability of Car Performance (how far car repeats distance performance on each of 3 trials) (5: excellent; 3: average; 1: poor)	5
Ease of use (can you easily get your egg in and out of the car) (5: excellent; 3: average; 1: poor)	5
Creativity:  How innovative is your car design, is it a Maserati or a Kia? (5: excellent; 3: average; 1: poor)	5
Did it meet design requirements:  (5: excellent; 3: average; 1: poor)	5
How good is your engineering drawing? (5: excellent; 3: average; 1: poor)	5
Total Score:	50

Materials:

·      Pipe cleaners: 2

·      Straws: 1

·      Craft sticks: 3

·      Cardboard

·      Wheels: 4

·      Axles: 2

Tools:

·      Glue gun with teacher’s assistance

·      Tape

·      Scissors

·      Rulers

·      Scale

·      Glue

Saving Humpty Dumpty Again

It was time for Humpty Dumpty with the Kindergartners again.  It is a bit rushed this year.  Our school has grown so large over the past two years that in the time that I have been working with the school we have grown from 4 classes to 7.  Getting to all the classes is a challenge, but we managed it this year.

This year in our 30-35 minute sessions we discuss what an engineer is.  Again, from the first session with the kindergartners, they know I don't drive a train, and that I don't injuneer (help people who are injured), but some are still struggling a bit with the idea of designing, but most are getting the idea that engineers are people who design things.  Today, I told them they were to be engineers that designed a safety device to protect Humpty Dumpty from cracking after he falls off the wall.  We talked about a couple of safety devices that they were familiar with:  safety belts and airbags.  I then had them think about what kind of safety devices they would want if they jumped off a wall.  The ideas included a mattress, a pillow, a parachute, and a slide.  I told them to keep these things in mind as they built their designs.

This year our design kit included:

• a small paper cup
• two cotton balls
• a sheet of paper
• a paper clip
• 6 inches of tape
• 2 3 inch pieces of straw
• a popsicle stick
• and a 4 inch square piece of paper towel.

I am always amazed at the kinds of designs the kids come up with.  We had one with a paper parachute, and another with a kind of roll bar out of straws and the popsicle stick.  We had a couple of groups that tried the mattress idea, however, they learned that the mattress idea doesn't work too well.   Humpty Dumpty rarely lands on the mattress and usually cracks up.

Here we see the typical design which is the egg in the cup surrounded by paper towel, cotton balls and paper.  If they pad all sides this design usually works pretty well.   Often, the group forgets to cover the side or top and we end up with a cracked egg.  But that is okay, the lesson they take away?  Engineers are not always successful with their first design, and often have to redesign and retest.  They can also use their ideas and combine them with successful ideas they see and make a new design.

The most successful design this year?   A cup padded on the bottom with cotton balls, the sides padded with paper towel and cotton balls, and a roll bar over the top made from straws and popsicle sticks.  One of the most innovative designs?  It was a cup heavily weighted and padded on the bottom but open on the top, with only a rubber band holding the egg in.  The weighted cup always landed with the cup underneath and the egg right side up.  It was an unexpected solution!

The Spark: A Radio Interview

Just last week, Martha Woodruff from WMRA and the host of The Spark aired an interview that we had in October.  I was thrilled with the results.  I just had my first call this morning asking for some of my activities for a school near Norfolk.  Thank you Martha!

If you are interested, here is the link to the interview:  

Robot Expert's "EaSiEE as Pi" Project

If you find this and are interested in the activities that I do, just email me.  I would be happy to help.

What keeps me coming back

As I sit here nursing my second cold of the year wondering if all the colds and flus are worth it ( yes, elementary schools are germy places) I just received a note in my email written to me by a student's mom.  Here is the text:

My son loved the class on making thermometers and wrote in his journal,

"It was awesome! It was very, very, very epic!" 

 This is what keeps me coming back to the school each week despite all the germs!  I figure if I can just reach a few students and get them excited about science and engineering then this program is a success.

Thermometers for Fourth Grade

Last week we made thermometers in fourth grade.  One of the standards is to understand that temperature is the measure of thermal or heat energy in the atmosphere.  The students are required to use a thermometer to compare air temperatures over a given time period.   So, to help them better understand thermometers and the idea of force, we have them build a thermometer.  There are lots of directions on the web, but I started with the Teach Engineering site.  The activity is directed toward fifth graders, and is mainly about making a scale and comparing their own scale to a celsius or fahrenheit thermometer.  However, we concentrate just on making the thermometer itself and getting the students to explain to me exactly how it works.  Here is a great photo of a working thermometer and an enthusiastic student, excited to see the apparatus working.

You start with a plastic soda or gatorade bottle.  If you use the gatorade bottle, you need to drill a hole in the cap to insert the straw.  For the soda bottle, just use the bottle as is without the cap.  CAUTION:  water bottles will not work!  We found out the hard way that water bottles will not work.  The manufacturers have taken so much plastic out of the water bottles that they are very thin walled.  The walls are not strong enough to resist the pressure changes and they will not work.

You will also need a mixture of rubbing alcohol (1 to 1 ratio), a straw, and clay.  I also have a bucket of ice on hand, containers for iced water and very warm water, say 110 degrees or so.

Here is copy of the sheet that I use:

EaSiEE as Pi^TM

Engineering and Science in Elementary Education

Thermometers

1. Place the straw in the bottle with the alcohol/water mixture but do not let it touch the bottom.

2. Use clay to seal the neck of the bottle by making a snake out of the clay, wrapping it around the straw and putting it on the opening of the bottle.  DO NOT shove the clay in the bottle, but just seal the top and around the straw.

You now have a homemade thermometer.  Test it and see if it works.

1. Cup your hands around the bottom of the bottle and see if the water/alcohol in the straw rises.  What is the approximate temperature of your body?  What is approximate room temperature?  What is the difference between the two?

If your thermometer doesn’t work, what could be wrong?  What are the three parts of the design.  What do you think you need to fix?

1. Put the bottom of the bottle in warm water, what happens?  What happens if you put it in ice water.  Keep observing the bottle, does something interesting happen in the alcohol/water mixture?

1. Why does the water/alcohol in the straw go up and down with temperature?

4.  Did you see bubbles in the water/alcohol mixture when you put it in the ice water?  Where did the bubbles come from?  Can you explain the phenomena?

Here are some students, getting the straw to the right height, and one of our wonderful volunteers looking on.

Here is a good photo of a thermometer working.  I color the water and alcohol mixture so that it is easier to see.  It is not easy to find clear straws.  Usually, you have to purchase them at a restaurant supply store.  But be careful, I did purchase some that were clear, the only ones they had, but they were brittle, so we had to go with the light colored straws.  The white ones that you can find are usually a bit opaque and not great for this application.  You can see the clay at the top of the bottle around the straw.  Also, this time, I could only find the straws with the flexible section.  You can cut them off, but it often makes them too short for the bottles.  Instead, have them place the flexible piece down inside the bottle. If you place it at the top, it often results in an air leak and a non-working thermometer.

The key to this device is the seal.  If the seal is not airtight, then the thermometer does not work.  You can see that the water/alcohol will rise just by heating with the hands.  If the water/alcohol does not rise in fairly short order, then there is a leak at the top.  Caution the students though, that if they squeeze the bottle, the mixture will shoot out the top!  

What is happening?  The system is sealed, when working properly.  As you heat the alcohol/water mixture, the mixture expands, but it cannot expand into the air in the bottle because there is nowhere for the air to go, so the only place the water/alcohol mixture can go is up the straw!  With a little coaching and some leading questions, the students are able to figure this out on their own.  

This is a fun activity, and all of them enjoy it.  There is always a bit of excitement when they work!