I have been teaching my kids about circuits lately. They have been using the little 1.5 volt incandescent bulbs, wires with alligator clips, and D cell batteries. D cell batteries are also 1.5 volts. I had brought in every lightbulb in my house that had burned out so the kids could see all of the filaments floating around in the bottom of the bulb. I also brought in one working 40 watt incandescent bulb. I thought it would be fun for them to see if they could get the bulb to light. Because the bulb says 120 volts on the bottom, I didn’t think the students could get it to work. We had a limited number of batteries to even try to light the bulb.
I put the large light bulb in a station for free experimentation. I thought the kids had forgotten about trying to get the large bulb to light, so I put the bulb in my lamp. When they asked about trying to get the bulb to light again, I took it out of the lamp and told them they could try up to seven batteries. They tried the seven batteries and the bulb didn’t light. When they were puzzled, I asked them whey they thought it didn’t light. Showing the girls the print on the bottom of the bulb and inquiring about the voltage of the battery, they realized they needed more batteries. I explained to them that we probably didn’t have enough batteries. Their reply was, “PLEASE, PLEASE, PLEASE, can we try more batteries?!” Since they were so persistent, I let them. I expected there to be no change in the bulb.
About five minutes later, I hear the girls squeal with delight! You guessed it! They lit up the bulb! They had about 21 D batteries taped together end to end with masking tape down the length of them. By this time in class, about five or six students had joined in and were holding a section of the batteries to make sure they were completely touching end to end. One child was holding the wire from the positive to the negative end of the batteries. When they got the bulb to light a little, they wanted to add more batteries to make it brighter.
What’s even better? With a tiny bit of prompting, the kids were doing real world decimal addition/multiplication. They were counting the amount of volts they had on each battery and figuring out how much voltage they were using to power the light bulb. I am glad I gave into their pleading and never told them I didn’t think it would work :)! They will probably remember this MORE than anything I had planned to officially teach them!
The hardware store is a place brimming with possibilities for fun and cheap science experiments. Did you know you can buy light switches for $0.69, and a foot of copper electrical wire for less than that?! Not only that, but you can buy a couple of large D cell batteries for $1 at the Dollar Tree. I will admit I already had some batteries and light bulbs in a science kit at school. Lowes sells the wire for a few cents a foot. If you tell them you are a school teacher, and look a bit pitiful, then they will cut it into foot segments for you :). I actually bought the light switches because one of my students wondered how they worked. I bought one to break apart with a hammer, so the kids could see the inner workings of the switch. The others I bought for students to connect to the battery and the light bulb with the wires. The kids were really excited to experiment with this. We had already been building circuits, so I didn’t exactly tell students how to connect the light switch to make the bulb turn on and off. I let them figure this out with the information they had already learned.
Here’s a little secret. If you want really cheap light bulbs, you can get LED bulbs if you buy a small flashlight for a dollar at Wal-mart. Then break the flashlight with a hammer to get the bulbs out. You will get around seven bulbs if you do this. However, the bulbs I used for this were in a science kit, and I didn’t have to buy them. They were little incandescent bulbs.
The next thing you can do for really cheap fun is this. Get a regular light bulb that you would put in a lamp, place one out for kids to experiment with if they have already learned how to build circuits. Challenge the kids to make the lightbulb light up. I tell them they can use up to five batteries. The kids won’t be able to light up the bulb. I know this, but they don’t. Several lessons previous to this, I had kids really examine the writing on the batteries, and some students noticed the 1.5 v. I had also had them pass around some old blown out light bulbs to study the broken filaments and the writing on the bulbs. If they make the connection, they will realize that the bulbs need 120 volts. The batteries only provide 1.5 volts each. It would take A LOT of batteries to power the light bulb. More than they could stretch out on a table (but that’s my little secret, wink wink). The fun in this activity is asking…well, why didn’t that work?
(Sidenote: I only have a few of these items mentioned above for students to experiment with when they finish their work. I don’t buy a whole class set.)
I hope you now have some great reasons to do some cheap and easy science experiments!
Who knew? There are magnetic materials in dirt.
I have been doing a unit with my third grade students about magnets. We have been learning about the properties of magnets such as attraction, repulsion, and polarity. In one of the extension activities, students are required to place magnetic filings over a magnet to see how the magnet has north and south poles. Immediately I thought of the little games with the bald man and magnetic pen in which you drag the filings over the man’s head to give him hair. I thought, “Oh! I could buy several of those and cut the plastic to get iron filings!”
Then, when looking for one of these “Wooly Willy” games on the internet, I happened across a You Tube video about finding iron in dirt. I didn’t really think it would work, but…….
here is what a couple of kids found after school when I made sure this would work. Now, we didn’t do it exactly like the video. I gave the kids a stack of strong disc magnets which I purchased form Hobby Lobby for about $7. They put the magnets inside a plastic bag. When they rubbed the bag in the dirt, the magnets attracted no iron. What did work was for the kids to put the dirt in a container which they collected from under some trees. They brought the dirt inside and sprinkled it a spoonful at a time on the plastic bag with magnets inside. Then when they shook the bag off onto some construction paper, the magnetic particles stayed. They emptied those pieces into a petri dish, which you see above. Sidenotes: In our case when the dirt was damp from some rain, this method worked best. At first they collected dirt from underneath some gravel in a garden. I thought it wouldn’t work because that dirt didn’t appear to have any magnetic properties. It wasn’t until they collected the dirt underneath the trees that they found the iron particles.
Now instead of buying iron filings, I am going to let the students find their own before we do our polarity experiment. I think they will very much enjoy the trip outdoors! Even though it is January, it has been 70 degrees this week.
I wanted my students to enjoy their last class with me before the Christmas break, so I planned several stations for them to work on. The students really enjoyed the engagement of every station.
Station 1: Students picked out a pine cone and were instructed to find seeds inside the pinecone. I showed them a picture of what pine cone seeds looked like. I gave them magnifying glasses so they could look closely and deeply into the pine cones. I instructed them to draw a picture of their pine cone and to draw a picture of the seed. In preparation for the next station, I instructed them to find two more pine cones that were really “pretty” and “tree shaped”. I really wanted them to find two that were opened up really well so they could see the difference in station 2.
Station 2: I had students place two nice flared out pinecones in water. Students made predictions before they placed one pinecone in cold water and one pinecone in warm water. I have no sink in my room, so I had a gallon jug set up for the cold water and a crock pot set up with warm water for them to dip from with a measuring cup. Make sure to have paper towels on hand for any water that is spilled. Now, students can watch the pinecones for a while, but it will take about 30-45 minutes before students will see any changes. I make students look and notice what happened. I don’t tell them. Now the last group that does this station probably won’t notice what happens. They won’t have enough time in an hour long class period to notice the pinecones change.
(So what does happen? Pinecones close up when wet. Why does this happen? Pinecones don’t want to release their seeds when weather is wet because they want to allow their seeds to fly as far away as possible during drier weather so that they won’t compete with the parent tree.)
After students have noticed the pinecones closing up, make sure you leave time at the end of the stations to ask the students why they think the pine cones are closing up in the water.
In case you are wondering, yes the pinecones will open back up when dried out.
Station 3: What happens when you place a peppermint under water? After students have watched, then what happens when you place M & M’s under water? This experiment wasn’t that impressive in my opinion, but the kids loved it! The experiment works best in a white bowl. The plates were way too messy when kids tried to throw out the water. Water, of course, spilled everywhere.
Students predicted first what happened with the peppermint. Most guessed it would turn white, but few guessed it would streak the way it did. You must keep the dish still and not shake the desk to get the full effect of this.
After students watch the peppermint for about five minutes, have them predict what would happen when they place out M & M’s around the bowl. I bought the small ones so there would be more color. If students place them around the edge of the bowl, it makes a dramatic rainbow like this. Again keep the bowl as still as possible.
Station 4: Light up a Christmas light with alligator wires and batteries. This station by far had the biggest WOW factor for the kids. I didn’t give kids many instructions with this station. I wanted them to do experimentation to figure this out. I made the kids predict which type of batteries would work to light up the battery. They lit up a small LED bulb. (this wasn’t actually a Christmas light bulb). To get these bulbs I bought a $1 LED flashlight at War-Mart and banged the flashlight with a hammer until I broke it enough to get the lightbulbs out. It’s cheaper to buy bulbs that way :0. To light up the bulb students need at least three batteries placed end to end with at least two alligator clip wires–one each touched to the positive and negative ends of the battery. I used D batteries because I had a bunch in a science kit, but this will work with smaller batteries. I hovered around this station because I knew students might struggle here. I made it a point to talk about how scientists struggle until they figure things out. We talk about how Edison didn’t give up the first time his improvements of the light bulb didn’t work and they shouldn’t either. Now in reality, it would have been a lot cooler if I actually did have Christmas light bulbs, but I already had LED bulbs on hand so we used them.
ChristmasScience Here is an editable document I used when students visited science stations. This is nothing fancy, but you are welcome to use it for your classroom and make it your own.
This STEM lesson was more fun than I had anticipated. We picked up ice cubes with a piece of string. There are few materials needed. The materials are cheap and it doesn’t take long to carry out the lesson in the classroom.
You will need:
- an ice chest or freezer
- ice cubes (the kind you freeze in ice trays) make about 5 per student to make sure you have enough
- string (like the kind you fly kites with)
- styrofoam bowls
- table salt (one container should be enough for a class of about 20)
- small cups or containers to distribute the salt
- paper towels
First, we watched a video about how salting roads helps salt trucks melt ice and snow on roadways here:
Then I explained to the students that we were going to make a string stick to an ice cube and that they would be able to pick it up. I had the students predict how long they thought that it would take to attach the string to the ice. I realized mid lesson that the kids thought I wanted them to literally tie a string around the ice cube. I had to clarify that we were not lassoing the ice cube, but that the salt would make it stick if they were patient (insert lesson about perseverance and patience here, wink wink).
These are the student directions in order.
- In your bowl of water put 1 ice cube (I passed these out when I was ready for them to begin).
- Put a pinch of salt on top of the ice cube
- Lay the string on top of the ice cube
- One team mate needs to watch time (I had this on smart board). The other team mate needs to watch the ice cube and pull on the string when the predicted time is up.
- If your string doesn’t stick, make a new prediction and try again. Switch partners.
I had a sheet in which the students predicted, and I also took some of their predictions and wrote them on the board. Some students predicted up to 30 minutes. Eventually, I reeled this in and said it wouldn’t take 30 minutes. In honesty it takes somewhere between 30 seconds and a minute. Also, I reminded students that they would only need a pinch or so of salt on the ice cube. Some students think that the more salt they use the better the string will stick and end up using WAY TOO MUCH! The important part of this experiment is the waiting. I told students that if they added salt that they would need to add it a pinch at a time.
For those students who are successful, I challenge them to make more than one ice cube stick and predict how long it will take for more than once ice cube. I walk around with a ziplock full of ice cubes during this time. When students get more than one ice cube to stick it becomes a contest about who can get the most ice cubes to stick at one time. The most I had students able to stick was 5 ice cubes. Not many kids were able to do this.
After this experiment, it is fun to discuss more of the science behind why this activity works. Because I did this during a 30 minute slot at a summer camp, we didn’t really have time to talk much.
I hope you can enjoy this experiment with your students, too!
I did this with a group of kids during my summer camp, but this could just as easily be done during a classroom engineering lesson. We built soda straw rockets to land on Mars.
What was Mars you ask? Mars was a simple circle taped to the floor with masking tape.
You need is the printable which consists of rocket fins and body, and then you need straws, tape, and a sharpened pencil…and of course Mars!
Here is a synopsis of the building directions. Students take the rectangle and wrap it around their pencil lengthwise to make a tube. Then they tape the fins at the bottom. Next they scrunch the top of the tube around the point of the sharp end of the pencil to make a cone.
Next, they pull out the pencil and insert the straw. Now they are ready to blow through the straw to make the rocket land somewhere.
I could have made it more difficult by using rulers so there would be some conversation involved, but I just made it simple and let them use yardsticks. Surprisingly, some students had the yardstick turned around and measurement still proved to be an issue.
If they didn’t reach Mars, they had to go back and redesign their rocket to make it fly closer. Now, what if they did land on Mars the first time? Well, I just made them see if they could make their rocket fly differently, for example, could they make the rocket spin while it flew.
The best part is this whole lesson and rocket parts printable are here free on the NASA website.