Friday, February 10, 2017

FIRST LEGO League Jr. - Teaching Engineering to 2nd Graders

FIRST LEGO League Jr is a non-competitive LEGO based program for kids in kindergarten through 3rd grade. Each year a challenge topic is announced and each team decides on an idea to address the topic problem and they build model with at least one simple machine to illustrated their proposed solution to the challenge as well as a poster to explain their solution. FLL Jr. is a great introduction to the FIRST organization, which provides a framework a programs to promote engineering concepts for kids of all ages.

http://www.firstinspires.org/robotics/flljr

I coached my son's FIRST LEGO League Jr. as an after school program (Triangle Math and Science Academy) when he was in 1st and 2nd grade (2012-2014). My goal was to help the kids learn a little about the engineering skills used when designing and building with Legos.

FIRST LEGO League Jr. Season

My son's team's idea was a fire-fighting robot that could put out fires in areas too dangerous for human fire-fighters. They called their robot the LSV for Life Saving Vehicle and their team name was Fire Destroyers. Their model used a LEGO WeDo program running on the laptop to drive a motor attached to a geared turntable that would sweep the fire suppressant nozzle back and forth.

At the end of the season events are held where teams share their projects with other teams, exchange buttons and present their projects to judges. The FLL Jr. event may be a stand-alone event or may be paired with an FLL event where older kids compete. The judges at our event included Sam Last, FLL Head Ref for North Carolina, and Fiona Last-Powel, the FLL Head Project Judge for North Carolina. Below are some photos from our team's event.

First Lego League Jr. Poster and Model.

There always seem to be last minute program changes. 

Working out the last of the kinks in the flow programming!

Explaining their model to Sam Last, FLL Head Referee for NC.

In FLL Jr. everyone gets recognized for their effort.

And a run through the high-five line with Sam and Fiona and the other judges. 

What Can I Teach These Kids

There were the easy lessons at first, do not grab things from other people and take turns. I had them practice leading build projects following LEGO instructions and they quickly learned that they have to listen and help when someone else is in charge if they want people to listen to them when they are in charge, a huge lesson! And we did experiments to compare the strength of beams of LEGOs in tension and compression. But soon I felt like I was running out of ways to teach them skills that would useful in an engineering career. 

It was a constant struggle to keep the 12 first and second graders on task. If you spend too much time with one group, the others were quickly building cars and trying to see which was faster. There were also frequent crash from cafeteria tables when a car veered off track. 

After our regular season had finished, near the end of our 2nd year I noticed that the kids were very excited when an older FIRST LEGO League team demonstrated their competitive robot. And the team had the same excitement when we attended a local Lego SumoBot competition that Spring. There was something about robots competing head to head that got the kids excited. But how can I do this with young kids without getting bogged down with robot controllers and programming?

A possible solution occurred to me when my son and I were playing with the Lego Power Functions Kit. (This kit includes an Infrared Remote and IR receiver along with battery pack, motor, lights, switch and accessories. It is great value for $30!)

http://shop.lego.com/en-US/LEGO-Power-Functions-Motor-Set-8293

My son and I used the kit to build remote control cars at home and it dawned on me that if I added a second IR receiver and set both to the same channel I could use the remote to start two different cars at the same time. This would let the kids race cars side-by-side to see which was faster. Drag racing! I bet the kids will love this!

http://shop.lego.com/en-US/LEGO-Power-Functions-IR-Receiver-8884

So I pitched the idea of racing cars to the whole group (six 1st grader and six 2nd graders) and they wanted to started right then! 


Applied Engineering Lessons

Having the kids design and build a car each week provides the opportunity to explain and explore many facets of engineering in terms the kids can understand and observe. 

Documenting Your Ideas
Public Speaking and Presentations
Collaboration and Persuasion
Building and Deadlines
Product Testing and Measuring Results
Feedback and Optimisation

We started the process by explaining that when you are working on an engineering team it is important not just to have a good idea but you must be able to communicate your idea to others in a way they can understand. So we began by passing out pencils and paper and asking every student to draw something about their idea for a car. After 20 minutes we asked each child to stand up in front of the group and tell us about their idea and answer questions from the group. 

The rules of the presentations were simple, everyone's ideas are good, no one will criticize anyone else's idea or drawing and EVERYONE gets a round of applause after their 30-90 seconds of presentation. I was surprised how many of the outgoing (loud) kids were scared at the idea of sharing an idea with the group. It took some encouragement but everyone made it through the process of their first technical design presentation! And the oldest kids were in 2nd grade! This was awesome!

Next we divided the kids into two groups and told them to discuss their car ideas, select the design features they like and build a car (we changed the mix of kids each week). The teams had 30 minutes to build a car that we would race between two tape stripes on the floor, a distance around 4 feet. Exact distance and time were not a factor since we wanted only an A vs B comparison of who reached the line first. It was fascinating watching the kids promote their ideas and debate with their teammates over the benefit of one design feature over another. Doubly so after a few weeks and they began to build a knowledge base from their previous efforts. 

As the deadline loomed (5 minute warning, 2 minute warning)  the stress of delivering an engineering prototype started to show (teams with a complex design got frustrated). The first race was won by the only team to bring a working car to the starting line. Amazing engineering lesson! Done beats a incomplete build every time!

After the race the teams got another 15 minutes to update their cars before racing again. The kids quickly learned that complex designs with lots of gears and multiple motors can be difficult to get working.

In the following meetings we repeated the process and changed the grouping of the kids. In those last few weeks of school the kids had fun, experienced the thrill of competition and improved their building skills. They learned to build the cars not too tight or friction would slow them down, they learned about adjusting gear ratios to match wheel sizes and they compared direct motor drive, gears and belt drives and practiced working under the pressure of a deadline. They learned the importance of working as part of a group and how to negotiate features and quickly accomplish goals. They were practicing agile prototyping!


Conclusion and Recommendations

The new drag racing program was a success. The kids embraced the challenge, improved their problem solving skills and became considerate collaborators. They quickly learned many engineering lessons that I didn't figure out until after I had an engineering degree.

A great idea does little good if you can't explain it to others. 
You need to be able to promote your idea to your team. 
You must work with your team even if your idea was not selected.
Finished beats not finished every time.
Simple is better than complex.
Loose is better than tight when it comes to speed.

I feel that changing the mix of kids each week and only competing within our group helped avoid an us versus them mentality and help each student learn to work with their current team. This helped each team focus on the task at hand rather worrying over rivalry with another school or another team within our larger group.

We specifically disassembled the cars after each meeting. The kids wanted to get attached to the cars and save them between meetings. But the goal was not to have the kids hold on to their creations but to help the them learn and believe that they build a great car again at the next meeting. Disassembly also avoided the issue of "ownership" when the teams were mixed again the following week. The point was to teach them to come up with ideas that they can prototype, evaluate and iterate. And their designs improved as they internalized the lessons learned. Real engineering!

Teams of 3-4 may work better. We only had enough parts on hand to build two cars and limited time left in the school year so we worked with what we had and used larger groups. With enough battery packs, motors and IR kits you can support racing more cars at one time. 

There are plenty of untapped options for this framework. The cars could tow a box of books to teach the kids to design for torque rather than speed. Or use an inclined board and see which car can climb the steepest angle. Or tow a box of books up an incline. This could open up the discussion of gearing and using other Lego motors. And advanced options could include comparing motors for speed versus gearing and even motor datasheets for efficiency versus maximum power output.

I hope that some of the ideas here can help you get your kids excited about engineering!


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