Science Update January 2017

Update from Caitlin:

Pre-K: Last week, we took a break from learning about how animals eat and trying to eat like they do to examine some real animals live and in-person. We watched a short video about the life cycle of a darkling beetle, and saw how it starts as a tiny egg, hatches into a larva called a "mealworm," grows and sheds its skin, turns into a pupa, and finally becomes an adult darkling beetle. After our video, and a discussion of how to safely handle the mealworms, each student was given a shallow plastic dish with a mealworm in it for them to observe, and to handle gently if they so chose. Some students were a little squeamish about touching the mealworms, but many students were brave enough to let the mealworm crawl on their hand, and felt its tiny feet tickling their palms. After our observation, we put the mealworms into their habitat. The bottom of the habitat is covered with bran meal, which is what they live in and eat. They also like to hide under the bran meal, because they don't like the light. We gave them a few apple slices to eat, which is also their source of water, and they have become a fixture in the classroom that the students check in on daily and care for.

This week, we returned to learning about interesting ways that animals eat, and we learned about a special fish called the archer fish. We watched a video about how this amazing fish catches his dinner: when it sees a bug crawling around on the plants above the water, it shoots a stream of water out of its mouth and knocks the bug into the water, where the fish can eat it. The scientist in the video told us that the archer fish is very good at being able to aim the stream of water as he spits, even at targets up to two feet away. We tried eating like an archer fish. Each student was given a small paper plate with three gummies attached to it (the gummies had been moistened with water and dried onto the plate). They were given a larger plate and a plastic pipette. The larger plate was filled half way with water, and the students had to pretend to be archer fish by sucking the water from the big plate into their pipettes, and shooting it at the "bugs" on their small plates. The rule was that students were allowed to eat the gummies, but only if they managed to get them to fall from the small plate by shooting them with water. 

Pre-K SpEd: To kick off our dinosaurs unit, we had a dino-dig. Students used their hands to dig into a tray filled with sand, where sea shells and an assortment of small plastic dinosaurs were hidden. 

Kindergarten: Continuing to think about how a material like paper is not very strong, but can be made into something strong like a box and our papier mache cups, I gave the students a challenge: using only a single half-sheet of newsprint paper and a single piece of tape, they had to build something that would be strong enough to hold a paper plate off of the table high enough for a marker to roll underneath it. If the paper could hold up a plate, the next challenge would be to hold up a small bottle full of water. They were allowed to fold, roll, or crumple their paper, but not to tear it. Students tried many different strategies, but we found that the best way to meet both challenges was to roll the paper up into a cylinder and tape the side. We have already observed that paper can be made stronger by layering it and adding glue, like the box and our papier mache, but now we had discovered something else that we could change about our paper to make it stronger: its shape! A paper cylinder was much stronger than crumpled or folded paper, and it could hold as many as 4 bottles of water before collapsing. If we added layering to our procedure by folding the paper before rolling it, it could hold as many as 8 bottles! So, now that we knew that changing the shape of a material could make it stronger, our next question was, what is the strongest shape you can make. On Thursday, we reviewed some of the three dimensional shapes that they have already learned about: cube, rectangular prism, triangular prism, triangle-based pyramid, square-based pyramid, cone, cylinder, and sphere. We decided to build a few of these shapes to test which is the strongest. Using toothpicks and play-doh, students constructed cubes, triangular prisms, and both kinds of pyramids (we realized that we couldn't build shapes that had round edges, because our toothpicks were straight lines). After building the shape, the students were asked to try testing its strength by putting pressure on its sides, its corners, and by picking it up to see whether it would hold together. We discovered that a cube was the weakest shape. It would wobble with only a little pressure on any of its corners, and if you tried to pick it up, it would fall apart. Our triangular prisms were a bit stronger. Sometimes the pushing on the corners would make it wobble, but it depended on which way the shape was oriented. It also fell apart when it was picked up. Next was our square-base pyramid. That was very strong if you were pushing on the top corner, but if you turned it on its side and pushed one of the bottom corners, it wobbled. When you tried to pick it up, it mostly stayed together. Our strongest 3-D shape was our triangle-base pyramid. No matter how you turned it, pushing on the corners didn't make it wobble. You could pick it up, roll it around, even toss it back and forth between your hands, and it would stay together. Why were some shapes so weak, while other shapes were so strong? We looked at our different shapes, and thought about the 2-D shapes that made them. A cube is made up of all squares. A triangular prism is three squares joined together in a triangle. A square-base pyramid is four triangles and a square bottom. A triangle-base pyramid is made up of only triangles. We realized that the more triangles our shapes had, the stronger they were, and we concluded that between a square and a triangle, a triangle is much stronger.

This week, we began by reviewing what we had learned about shapes and that, so far, our strongest 2-D shape is the triangle, and the strongest 3-D shape is the triangle-base pyramid. After the review, I told the students that we were going to take a short break from thinking about shapes, and think about houses. Giving each student a half-sheet of paper and 3 minutes to work, I asked everyone to draw a picture of a house. After we had drawn our houses, I shared the designs different students had drawn. We looked through many different pictures, and I asked the students to think about what shapes they observed in each house. We noticed a pattern: almost everyone had drawn a house that was made of a square bottom with a triangle on top. Even between the three classes, most students had drawn a house in the same shape. Why was this? Why does everyone draw the same shapes when they think of a house? I explained the students that here in the U.S., most houses that people live in and that we see in books, tv, and movies, are shaped that way. So it is natural for us to draw houses in shapes that we are used to seeing. We looked at a chart of the most common kinds of houses in the U.S., and we saw that many had the same shape, and that big buildings like apartment buildings and condos were also squares. We then looked at some other houses from around the world. Some other countries had similar houses (like adobe houses), but some houses had very different shapes. A teepee was shaped like a cone, and an igloo, a yurt, a hut, and a wigwam were all shaped like half-circles. I then showed the students a picture of an indigenous-style house from India, which was in the shape of a half-cylinder. We also observed that the house was made of grass, or straw. I asked the students if they had ever heard of someone building a house of straw, and indeed, they knew the story of the three little pigs. In the story, a house made of straw is not a very strong house at all. Why did the people who built this house use straw, then? Some students guessed that they hadn't heard the story, or that they weren't very good builders. I asked the students what houses in the U.S. are usually made of, and they listed wood, brick, cement, and metal. I asked whether those are strong materials, and they agreed. I then asked why the people who built the house pictured hadn't used bricks or cement, and it dawned on some of the students that the people who built the house didn't have bricks, cement, or other strong materials to build with. They built the house of straw because straw was the material they had. But even though the material wasn't very strong, the people still wanted a strong house to live in. What could they do to their material to make it stronger? After thinking and referring back to our paper challenge from last week, the students realized that by making the house into a half-cylinder shape, it was much stronger. It wasn't that the people weren't smart, or not good builders. They were using the materials they had in the best way possible. On Thursday, we took some time to look at the houses again, and think about how shape and materials both work to make something strong. We recalled that shapes with triangles were stronger than shapes with squares, but how did circles compare? We began by re-enacting the water bottle challenge, this time with paper that had been folded into a cube, into a triangular prism, and a cylinder. We saw that a paper cube could hold only 3-4 bottles of water, and a triangular prism had similar results, while our cylinder could hold 8. It seemed as though the circle in the cylinder was stronger than the triangle or the square. I showed the students an egg, and asked them whether eggs are weak or strong. Most agreed that eggs are weak and easy to break. Easy enough to break just by squeezing in my fist? Most students thought so, and were surprised to see that I couldn't break it by squeezing it. Sitting in a circle, each student was given a chance to try to break the egg by squeezing it, but try as they might, no one could. Some students suspected that the egg was fake,  or hardboiled, but once it made the round, I cracked it into a basin to show them that it wasn't a trick; the egg really was that strong. The eggshell itself was very thin, and I broke a fragment with my nails to show the students how fragile it was. So why couldn't we break it by squeezing? Because of its shape. Round shapes are very strong when there is pressure coming from all sides at the same time. To see how strong, we took a flat of 3 dozen eggs and had the students try standing on them. They were amazed and thrilled to see that the eggs did not crack. 

 

(There were several surprises, however.  After students in Room 2 tried standing on the eggs, they asked Ms. Griffith to try. She was able to last year, but this year, we had several cracked eggs. We also had a student crack eggs in Room 3, but that was because he rocked backwards on them. The biggest surprise, including for me, was during Room 4's science class. After the first egg had made its round through squeezing, I took one last squeeze, joking that maybe the students had weakened it for me. Perhaps they had, because, for the first time after having done this lesson at least a dozen times before, the egg burst in my hand and exploded everywhere. Luckily, I had clean-up supplies prepped and ready.)

 

Vocabulary: cube, rectangular prism, triangular prism, pyramid, cone, cylinder, sphere

Try this at home: Using blocks or other materials, try building some structures with your child and seeing which ones are strongest and most stable. Think about what makes one structure stronger or more stable than the other, and what you could do to strengthen a weak structure. (This will be a big part of our engineering unit, beginning next week.)

First Grade: Last week, we reviewed how an anemometer and a pinwheel work, and that they are both instruments that meteorologists use to measure wind speed. We then watched a short video about measuring the wind, and I told the students that the video would discuss three instruments, one they knew about, and two new ones. I told them to listen carefully for the names of the new instruments, and what they measured. After watching the video, students were quick to name the anemometer as the instrument we already knew about, and that it was for measuring wind speed. The two other instruments mentioned in the video were a wind vane, and a wind sock, which tell where the wind is coming from, and where is is going. The video also told us that wind direction is described in terms of compass directions: North, East, South, and West, and that when describing the direction of the wind, you always talk about where the wind is coming from, not where it is going to. For example, a wind that is blowing toward the South is a Northerly wind. I showed them a wind vane that I had built, and we observed how the arrow always pointed into the wind, showing you which direction the wind was coming from. After learning about our new weather instruments, it was time to build another weather instrument that is more commonly used as a toy: a kite. Students took their kites home.

After reviewing the wind vane and wind direction, this week, we went back to what we had learned about air back at the beginning of the unit, about how air can push and pull. I asked the students to think about the kites that they had made last week, and what we had learned about the wind scale some weeks before. You can't fly a kite in calm, or even in a gentle breeze. Why? There isn't enough wind to push the kite up. In a moderate breeze, the wind is moving fast enough to push the kite up. We know that air is pushing the kite up, but what is pulling the kite down? Gravity! If the force of gravity is stronger, the kite will sink and fall. If the force of the wind is stronger, the kite will rise and fly. To demonstrate what we would be thinking about during the lesson, I took out a model parachute made from a paper napkin, string, and a paper clip. I asked the students to think about what forces were working on the parachute. The parachute fell to the ground, but not as fast as a paperclip would have by itself. The force pulling the parachute down was gravity, and the force slowing it down was the air. I told the students that this force of air pushing against the parachute had a special name: air resistance. We then watched a short video about how parachutes work, and I asked the students to pay attention to the word that the video used to describe air resistance, because they would use a different word to talk about air pushing against things. In the video, they called air pushing against things drag. We realized that the best parachute would have a lot of air resistance, or drag. That would make it fall slower, and the best parachute is the one that falls the slowest (because it keeps the person using it safest). On our parachute worksheets, I had the students label a diagram showing a parachute with the forces moving the parachute. I then showed the students a second parachute, and before releasing them, we compared them. They were both weighted with a paper clip, attached with four pieces of string and stickers, and the size of the chute was the same. However, one chute was made of a napkin, and the other was made of newspaper. Would they work the same way? Releasing both at the same time, the newspaper parachute reached the ground before the napkin parachute. So which was the better parachute? The napkin makes a better parachute, because it creates more drag. I told the students that I had several materials for them to make their parachutes from: napkins, newspaper, plastic, and paper bags. Each student was to write the question: "I wonder what will happen if my parachute is made of ___________________?" on their worksheet under the parachute diagram, and to fill in the blank with the material of their choice. We then built the parachutes, which the students took home (we didn't have time to compare student-built parachutes, but we will be comparing the different materials next week.

Vocabulary: anemometer, meteorologist, instrument, wind vane, wind sock, North, East, South, West, gravity, air resistance

Try this at home: The parachutes we made were not built to last, and probably fell apart by the end of the day. However, it is very easy to build another parachute, and you can build a few with your child and test different materials at home to see which would make the best parachute.

Second Grade: Last week, we observed that although milkweed bugs, silk worms, and painted lady butterflies are all insects, they do not have the same stages of their life cycles. While they all begin with an egg stage and end with an adult, from which future eggs come to continue the life cycle, silk worms and painted ladies go through stages such as "larva" and "pupa," while milkweed bugs go through a "nymph" stage. We learned that all insects go through a process called "metamorphosis," but that metamorphosis has two variations: complete and incomplete metamorphosis. Since metamorphosis is a big word, we broke it down into two smaller parts: meta, meaning "beyond," and morph, meaning "shape" or "form." An organism that undergoes metamorphosis is one that goes beyond the shape or form that it is born with. Some insects are born looking nothing like their adult parents, such as the painted lady caterpillars. To reach the adult stage, they have to completely change their shape. To go through such a drastic change requires a pupa stage. This is called "complete metamorphosis." Other insects, like our milkweed bugs, emerge from the egg looking like a tiny version of the adult, called a "nymph." The nymphs grow and shed their outer skins until they are adults, but they change only a little bit, so they don't require a pupa stage for intense growth and transformation. This is "incomplete metamorphosis." We watched two short videos about other insects that undergo metamorphosis: a luna moth undergoes complete metamorphosis, going from larva to pupa to adult, whereas a mantis is born a nymph, shedding its skin as it grows, undergoing incomplete metamorphosis. 

This week, we delved deeper into variation and where variation comes from. We read a section in our book called "Environment," and we learned that every organism has "characteristics" that make it a unique individual (similar to "properties" when we were studying geology). Some of these characteristics are inherited, passed down from parents to offspring. However, others are the result of environment. An example in our book was a darkling beetle. A darkling beetle has certain inherited characteristics, such as its body plan (head, thorax, abdomen, six legs), and its color. However, some beetles have characteristics that result from the environment, such as a broken wing cover or a missing leg. Some of these characteristics will be passed onto its offspring. The beetle's offspring will have the same body plan and coloration. But its offspring will not have a broken wing cover, or a missing limb, because those characteristics are environmental. We learned that variation, especially inherited characteristics, can have a big impact. We watched a short video about the differences between artifical and natural selection. The video taught us that for as long as people have been farming, we have been selecting organisms with preferred characteristics, such as sweeter, larger fruit, or more meat. In each generation, there is some variation, and farmers choose which characteristics they like the best, and allow only those organisms to reproduce. The farmer doesn't actually create anything, only chooses. In natural selection, it is nature that chooses which animals will live and reproduce. It isn't making a conscious choice like a person does, but simply by natural processes and forces, some variations will be selected for. The video showed us that many vegetables that we eat such as kale, cabbage, brussel sprouts, broccoli, and cauliflower, all came from the same weed. After watching the video, I revealed to my students that all these vegetables are brassica, just like the plants we have been observing in our classroom. The brassica we are observing is not going to turn into a vegetable, but it does come from the same plant that kale, cabbage, etc. come from. We also looked at selective breeding in two other plants. I showed the students a picture of Queen Anne's lace root, and asked them what they thought farmers might have selected it to become. They were very surprised to see that the small, tangled root of the Queen Anne's Lace was turned into carrots! They were equally surprised to learn that carrots have only been orange for about 300 years, and that farmers selectively bred the orange carrot from yellow, white and purple varieties to honor William of Orange. We also looked at how far bananas have come from the tiny, starchy fruit full of big black seeds in the wild to the large, sweet, seedless fruit we know today.

(Note: Due to the holiday for Chinese New Year, and because we will be starting the engineering project next week on Thursday, Ms. Guillen's class did not have the lessons about metamorphosis or selective breeding. This week, they had the preparatory lesson for the engineering unit that the other second grade classes will have this coming Tuesday.)

Vocabulary: larva, pupa, nymph, complete and incomplete metamorphosis, head, thorax, abdomen, variation, environment, inherit, characteristics, artificial and natural selection, selective breeding

Try this at home: Choose a favorite food and do some research into its origins. Almost every plant or animal that we eat has been selectively bred for hundreds, if not thousands of years. You may be amazed at what you learn!

Third Grade: Last week, we used the collaborative moon phase poster we completed in the previous lesson, and worked on individual moon phase charts that went into our notebooks.

This week, we completed the moon phase charts, and watched a video called "All about Stars," in preparation for our final lesson next week about stars and constellations. The students had to complete a guided worksheet for the video, filling in the blanks for different facts about the stars, such as how many they are (billions), what they are made of (hot gases, hydrogen becoming helium), the life cycle of stars (sometimes they explode in a supernova), their colors(blue, white, yellow, orange, and red, with blue being the hottest), and how telescopes work (lenses and mirrors collect light from stars, with inward curving mirrors collecting the most light).

 Vocabulary: lunar cycle, phase, new moon, waxing, waning, crescent, gibbous, full moon, stars, 

Try this at home: We will be having a guest speaker next week to share some information about the constellations. Weather permitting, take some time to examine the night sky and see which constellations you can identify. The speaker will also give a little background about the different cultural origin stories behind different constellations. If you know any of the stories behind the constellations you can spot, share them with your child, or feel free to make up your own together.

Update from Paige:

5th grade: Mr. Ellingson and Mr. Calubaquib
The most exciting experiment we have done in the new year occurred about two weeks ago. Thanks to the help of first grade parent, Susan Koo, our students had the opportunity to see a fresh pig heart, lung, and other tissues. A big "Thank You" to Susan!

We have been studying how cells get what they need to live.  It's pretty straightforward for single-celled organisms, but multicellular organisms (organisms made of many cells) have to have more elaborate systems to get resources to all of their cells. Previously, we studied how vascular plants solve this problem.  Now, we have been looking at how humans solve this problem.  In this study, we were trying to understand more about the circulatory and respiratory systems.  

We had four stations through which students rotated.
1.). The first station had laptops with pre-selected YouTube videos related to heart function.
2.). The second station had human models of the heart borrowed from Stanford and UCSF.
3.). The third station had models of the heart/lung in combination also borrowed from Stanford and UCSF.

4.).  But the truly awesome station was station 4. The fourth station had a pig heart specimen and a pig heart/lung specimen.  As an anesthesiologist involved in organ recovery, Susan was able to get access at Stanford to dissect two pigs and bring us fresh samples to examine in class.  Susan had dissected the heart, so students could see that the addition of liquid to the left ventricle caused the valve to close.  Susan had set up the pig heart/lung specimen, so the lungs could be inflated using an external hand pump.  It was incredible to see the lungs fill up with air and then deflate!  Honestly, it was an amazing experience!


4th grade: Ms. Washington, Mr. Calubaquib; 4th/5th Mr. Briggs

My favorite experiment in 4th grade this month was an experiment looking at how the distance between magnets changes the strength of the magnetic field.  We did a really cool experiment using a balance to explore this topic.  On one side of the balance, there is a magnet on a post attached to the balance base.  On the balance arm, there is a cup.  We put a second magnet in the cup that was attracted to the magnet attached to the base.  On the other arm of the balance, we put metal washers in a cup.  When the force of gravity acting on the washers exceeded the magnetic force holding the magnets together, then the balance would tip as the two magnets came apart.  We recorded how many washers it took to break the magnetic force.  We repeated this experiment, but we added small plastic discs (spacers) between the two magnets.  We recorded how many washers it took to break the force when the magnets were separated by 0, 1, 3, 4, 5, or 6 spacers.  When we graphed the number of washers vs. the number of spacers, we saw there was a relationship.  It’s actually a totally beautiful exponential curve:)  We talked about how we could predict how many washers it would take the break the force between magnets separated by 2 spacers.  After making a prediction, students tested how many washers it took, and lo, and behold, the predictions were nearly always correct.  Totally awesome.  Students talked about how the data showed that as the distance between magnets increases, the force between them gets weaker.  


3rd grade: Ms. Song
We started our unit called "Sun, Moon, and Stars" when we returned from winter break.   We began by looking at the sun.  Our first question to investigate was does the sun appear to move in the sky? We approached this question by recording where the sun was in the sky three times during the school day. In addition, students also drew their shadows on the concrete while standing in the same position each of the three times they were outside.  The next week we looked at the data. First, it was apparent that the sun does appear to move in the sky throughout the day. Moreover, the sun rises in the east and sets in the west. Next, we looked at the data of one student's shadow study. We saw that the size and direction of her shadow changed throughout the day.  To try to explain this phenomenon, we developed a model for what was happening. In our model, we used a flashlight to represent the sun, a cork to represent the student, and the table represented the ground. Students were challenged to try to determine why the shadow changed size and direction throughout the day. Through this study, they realized that shadows are created by objects blocking the light. They also realized that the sun moving through the sky from East to West explained both the change in size and direction of the student's shadow. When the sun is closer to the horizon, shadows are longer. When the sun is closer to overhead, shadows are shorter. When the sun is East of the student, the shadow is on the West, and vice versa.  In the end, we also looked at a model in which the earth was a globe, the light source was a flashlight, and the person was a small slip of paper on the surface of the globe. I explained, as most students already knew, that the sun doesn't move, but instead, the earth rotates on its axis, making it appear the sun is moving.