Tuesday, February 20, 2018

Stock Market Game

I love this competition. This one is all about Math, but what a great and fun competition it is!

So, the premise of the Stock Market Game is that each team gets $100,000 to invest for the competition period. There are three awarded competition periods - 8 weeks in the fall, 8 weeks in the spring, and a year-long competition that runs from Oct to Apr. Teams that place 1st, 2nd and 3rd receive awards from the Stock Market Game organization.

The United States is divided into regions, and top 3 regional winners are invited to an award ceremony. In northern California, the award ceremony is held at the Bank of America building in San Francisco.

The 1st page of the website. This website offers a lot of resources for the teachers to use in classrooms. You can also request a professional to come out to your classroom to do a presentation to your students. I have several kids participating in this program as an after-school activity. So, that's an option for you to consider as well. The regional manager I interact with is great. She is responsive and prompt. 

This is one of my team's rankings in the year-long competition. This team was ranked as high as 3rd in Dec/early Jan but fell in the rankings since. The key to this competition is to encourage your students to trust their research and NOT to be impulsive when stocks are sliding. And not to trade too often. One teacher I know limits trades to 3 trades in the 8-week competitions.

This shows how much of a team's money is invested and how much  is held in cash.

This screen shows the top holdings of all the teams that are participating in the competition. Yes. You do see a lot of usual suspects, but I also encourage my student to dig around a little and find at least three stocks on their own (these would be stocks you wouldn't normally see on the top holdings list).

Other programs the Stock Market Game offers.

Why do I like this so much? I find that this website makes Math come alive for many of the students. Before we start, I have the students do research stocks and ask them to compare the stocks they like (we look at short-term, 2 months, and long-term, 7 months performance) and tell them to decide based on their research and calculations.

It's amazing what kind of responses I get. One time, I saw a stock symbol I've never seen before and asked a student about it. And she said, I know my money could do better in big name stocks, but this pharmaceutical company has a kidney cancer drug coming up for FDA approval in next February (meaning right now), and it’s going to take off. According to my research, it is highly likely that the drug is going to get approved because it's already doing well in another cancer study. 

Isn't this an amazing explanation? I didn't expect that from a 6th grader. 

And it's also fun to say, "Don't you want to know how your investment is doing?" when a student asks, "Why do I have to learn long division?"

I guess I like this program, because it's SO much more than just about stocks.

And the best part? It's not too late to participate in the spring or the year-long competition. So, why don't you check it out? 

Have a great day.

Monday, February 19, 2018

Attaining Invisibility!

Did you ever wish you had Harry Potter's Invisibility cloak? 
I certainly did when I read the books and watched the movies. 
So, do you think you can be invisible? 
It all depends....

Our eyes...

First, let's talk about how we see (how things become visible to us).

Some facts about how we see:
  • Light rays are reflected from a surface in straight lines. 
  • When light rays hit a smooth surface, the light rays are reflected back at you.
  • When those light rays enter our eyes and hit our retinas, an image is formed (upside down)
  • When light rays hit an uneven surface, the light rays are scattered. The reflected light bounces off in all directions, unable to form a coherent image.

Do you see the light colored blob in the bottom of her eye? That's me, reflected in her eye. Isn't it amazing?

So, how do we achieve invisibility in Real Life? 

How about a stealth fighter plane/helicopter/ship?
  • As the radar antenna turns, it emits extremely short bursts of radio waves, called pulses. The pulses move through the atmosphere almost at the speed of light. By recording the direction in which the antenna was pointed, the direction of the target is known. The better the target is at reflecting radio waves, the better it will be able to attain invisibility.
  • Stealth technology cannot make the aircraft invisible to enemy or friendly radar. All it can do is to reduce the detection range of an aircraft. This is similar to the camouflage tactics used by soldiers in jungle warfare. Unless the soldier comes near you, you can't see him.
  • Reduce radar cross section
  • Change vehicle shape to reflect radio waves in all directions
  • Use new technology to absorb/trap radar waves
  • Use of non-metallic airframe
A simple experiment on invisibility

For this experiment, you'll need large piece of foil (large enough to see your face in). 
  • Be careful to cut/tear that piece of foil without crinkling it at all.
  • Smooth it out (don't touch it too much) and look at yourself in the foil. Sure. It's not like a mirror, but you should be able to make out your facial features.
  • Now, crumple that sheet of foil into a fist-sized ball.
  • Then, open it up and smooth it out as well as you can.
Now, can you see yourself in the foil? You can't. So, why do you think you can't see yourself at all in the same sheet of foil?

When the foil is scrunchy and rough, the reflected light bounces off in all directions. And because these reflected rays are going off in all directions, your face does not form in the way it did before.

This is a very simple experiment, but there's a lot to learn from it. For deeper learning, search for pictures of stealth planes, stealth helicopters, stealth ships, etc. There are a lot of angles on the vehicles. Not smooth like the traditional vehicles.

Have fun and enjoy the day!

Friday, February 16, 2018

Elephant's Toothpaste

I haven't done many Chemistry experiments in class, because there isn't enough time to clean up the mess before the next class comes in, etc. But I always wanted to try this one (even though there are many variations of this on youtube and elsewhere) because any kind of foaming, explosive reactions I've done before were based on vinegar and baking soda (any this one is based on hydrogen peroxide). And it's always really fun to get your hands dirty.

This is what we're doing today. 
This was the extent of the mess I had to clean up from this experiment, which is less than I expected.

List of supplies:
  • Empty plastic bottle
  • Baking tray (bigger the better)
  • 4 fluid oz of hydrogen peroxide (3% concentration is the one I used. I bought it from a nearby pharmacy)
  • Dish washing liquid
  • Dry yeast
  • Hot water
  • Funnel
  • A small bowl to mix yeast and hot water
  • A measuring spoon set (1 tsp & 1 Tbsp)
  • A spoon to stir the yeast and hot water mixture

Measure 4oz of 3% concentration of hydrogen peroxide.

Pour hydrogen peroxide into the empty water bottle along with a couple of drops of food coloring and a couple of drops of dishwashing liquid.

Mix a 1 tsp of yeast with 2 Tbsp of hot water.

Using a funnel, add the yeast and water mixture to the hydrogen peroxide in the bottle.

Too bad I didn't do this experiment a couple of days ago. It has a nice heart shaping going. It's probably more impressive in person than in picture.

Big bubbles on the left outer edges of the foam mixture (bubbles from earlier reactions).

Big bubbles on the left outer edges of the foam mixture (bubbles from earlier reactions).

Smaller bubbles in the closer vicinity of the plastic bottle (bubbles from the later reactions).

SO..., why does this happen? Think about what happens in the bottle.

Science notes:

Well, if hydrogen peroxide is left alone long enough, it'll break down to water and oxygen on its own. BUT, by adding yeast into hydrogen peroxide, we're speeding up the break down process.
  1. The hydrogen peroxide locks on to the yeast.
  2. The yeast breaks down into oxygen and water.
  3. The oxygen released by the yeast mixed with dishwashing liquid creates the bubbles and produces the foam.
  4. And this one, you can't tell from looking at the pictures, but when I touched the water bottle, it was warm.
  5. Hydrogen peroxide + yeast is an exothermic reaction (heat-producing), and that's why the water bottle was warm to touch.
I liked this experiment a lot because it was simple and even though there was a mess, it was easy to clean up after I was done.

I'd like to do this in class varying the concentration of yeast and water mixture. I'd like the students to figure out the relationship between the yeast concentration and the amount of foam (which probably is hard to measure) or the amount of heat the experiment released (which probably is also hard to measure). Also, I can play around with different concentrations of hydrogen peroxide. Anything over 6% concentration is not recommended online.

Again, for a Chemistry project, this was fun, easy to clean up, and it offered a lot of opportunities to mix it up.

Have fun & have a great day!

NOTE: If you have really little kids around you, please make sure they don't consume the foam.

Wednesday, February 14, 2018

LEGO Technic Build (Mechanisms) - Page 146, Build #186

I'm building another cam today.

As stated in a previous blog, a cam is a rotating machine, which transfers a oscillating or reciprocating motion to another part known as a follower. A really good example of a cam is a car engine.

Pieces I'm going to use today.

I can't explain why, but I really like building cams. I had a lot of fun building this one, and I hope you have a lot of fun, too.

Have a great day!

Tuesday, February 13, 2018

Hoop Gliders

I came across these hoop gliders several years ago, but I revisited them with my children when we were participating in the Tech Challenge 2016, Taking Flight. And just like the Birds of PLAY, we made these gliders to prototype (we thought using the gliders in the shape of birds would be fun at the competition) and understand the mechanics of flight.

Before you start, throw a plain straw. Does it fly well? Not really. It’s because the straw doesn’t have wings. It has nothing to generate lift. But when you add hoops, they act as wings, generating lift. And depending on where you put the hoops, your hoop glider will generate more lift or less. You experiment with sizes and locations of the hoops and decide what works best for your hoop glider. 

 This is what we're making today. 

These are quite simple to make, and they are incredibly fun to throw and watch them fly. This is a great project you can do with your children/students inexpensively. I hope you try this project and have a lot of fun.

List of Supplies:
·                     Straws (different lengths and diameters)
·                     Paper strips (copy paper, construction paper, cardstock, etc., whatever you have handy)
·                     Scissors
·                     Adhesive tape

Cut the paper in 1/2" or 3/4" strips. You can experiment with other widths, but these are the widths that seemed to work best. I also have three different sizes of straws. For my convenience, I made my hoop gliders with the wider, pearl drink straws. But I had students make hoop gliders with regular straws, and they did well with the smaller diameters, too. So, it really doesn't matter too much. Again, if you have different sizes available, experiment.

These paper strips are 3/4" wide. I like this width for no other reason than that it's the width of scotch tape. So, that's the width I use, but I've seen other project instructions online with 1/2" width instructions. Tape the ends of the strips together and make circles. You can experiment with lengths, but I tend to use 3", 6", 9" and 12" strips. I don't know why. I think it's the proportions that matter, not the actual lengths.

You can put as many or as few hoops as you want. But the minimum number is 2.

Have fun with where you put the hoops. Go crazy and fail spectacularly!

As you see, the left hoop gliders hoops are not aligned. The hoop in the back is attached in the middle, but the hoop in the front is attached to the right handside. Play with where you attach the hoops - in the middle, left side, right side, etc.

Just want to show you the different sizes of the hoops I attached. Again, the goal of these projects is to have fun.

I made 4 hoop gliders this morning. but when I conducted this project in class, some students have made as many as 10+ gliders. So, make a lot and have fun.

How to throw a hoop glider. Gently throw it forward.


This one flew pretty straight and far.

This one flew the farthest, almost toward the fence & the rose bushes.

This one was interesting to look at slow-mo, because the largest loop would swing back and forth between left and right. But it didn't fly far.

This one was all over the place, but interesting to watch.

It's a perfect day to fly gliders! Have fun!