Second grade students learned that civil engineers design and construct roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways.
I explained that they were going to use the Engineer Design Process to construct a bridge with just two pieces of copy paper! The bridge must hold a car and a boat should be able to pass under it. No tape was permitted. They failed and then improved their designs multiple times. Just about everyone tried a beam bridge first. Then, I brought these engineers back together and after looking at arch and truss designs, I then sent them back to work. Folding the paper (like a fan) to construct triangles (truss) proved to be the most effective way to successfully complete this task.
Click here to learn more about bridges.
We noticed that cardboard is supported with triangles too.
In honor of Abraham Lincoln’s birthday, kindergarten scientists learned about the history of the penny and how coins are minted. Click here to watch a video about minting.We used hand lenses to observe the pictures, words, and dates on our pennies.
We observed that some pennies are bright, while others are dull. Oxidation causes pennies to tarnish. Oxidation is a process in which a chemical substance changes because of the addition of oxygen. Oxidation also occurs when metals rust and apples turn brown. We tried to clean off the oxidation with five different liquids. Most of us hypothesized that the soap would clean the pennies the best, but we discovered that the liquids which contained acids made the pennies bright again. Click here to learn more about this investigation. Try this investigation at home with different liquids such as, orange juice, tea, milk, shampoo, or Sprite.
We recalled from last week’s lab that water molecules bond together (cohesion). I asked my scientists to hypothesize how many drops of water they thought could fit on the surface of a penny. Most thought the number would be between two and ten. They were amazed when they were able to fit between 20 and 40 drops on their pennies! It didn’t take long for one of my scientists to notice that a water bubble (or dome) formed on top of his penny.
Before we left, I filled a cup of water to the very top. How many pennies can we add to the cup without the water spilling over? Each class was able to drop between 80 and 100 pennies inside!
Try this at home:
Collect pennies, look at the dates, and compare the backs.
If you don’t wash off the vinegar on the pennies, they will turn green. Why? The Statue of Liberty is green for the same reason – oxidation and acid rain. Click here to learn more about the Statue of Liberty.
Do you remember the carrot seeds my youngest scientists planted in October? We pulled them out of the soil today. Mrs. Hamon is going to feed them to her guinea pigs.
During the snowstorm, I sent my scientists some ideas for snow investigations to complete at home. Loved receiving photos of them at work!
I loved everything about this day! I sat in front of the fire reading, as I watch the unexpected snow fall. I imagined how excited my students felt finally seeing snow and imagined what fun they were having with their families. I can’t wait to hear all about their adventures when school resumes on Monday. There is something special about a snowstorm in Georgia!
Second grade engineers reviewed the names of solid shapes, including prisms and cylinders. Students paired and discussed which shape they believed would hold the most weight. Most of our debate focused on whether corners would or would not make the shape stronger. We weighed the books on a kitchen scale before we placed them on the pillars. We discovered that the cylinder easily supported the most weight. We looked at how cylindrical columns are used by engineers, but we recognized that God was the first engineer!
Next, I tasked my engineers with building cylindrical columns. They had many design choices, but teams were only able to use four pieces of paper. Masking tape, scotch tape, and rubber bands were available. Would their cylinders be tall, short, thin, or wide? Would more cylinders hold more weight? How does balance impact your structure? I witnessed collaboration and problem solving as they constructed their pillars. Several engineers used all four pieces of paper to make one stronger cylinder. Others made multiple cylinders and taped them together. What would happen if we made more cylinders and distributed the weight? There was much celebrating as they tested their designs. One structure held 24 pounds, but many others held at least 12 pounds! (Each book weighed 2 pounds.)
Try this at home with different types of paper and be sure to send me a picture! For additional directions click here. and here.
Scientists classify fruit as the part of the plant that protects seeds. Yes, that means a tomato is a fruit! Click here to learn the difference between fruits and vegetables.
My kindergarten scientists have studied sink and float concepts periodically since October. This time, we used what we knew about density to hypothesize which fruits would sink and which would float. We learned a lot because our results didn’t always match our hypotheses. We weighed the fruit first, but density and weight are not the same. We recalled what happened last October when we placed a jack-o-lantern pumpkin and a candy pumpkin in the water table. Our original thinking was turned upside down when the big, heavy pumpkin floated and the small, light, candy pumpkin sank. Although the apple and the pear were equal weight, one sank and the other floated. The kiwi was lighter than both, but it sank too. The grape, which was the lightest fruit we tested, sank. The orange floated, but when unpeeled sank. Hmmm…
Extend this activity at home. Select fruit at the grocery store and weigh them on the scale. How are the fruit alike and different? Research to discover the kind of tree or plant on which they grow and where those plants are found. Cut the fruit open and find the seeds. How are they arranged? How many are there? Taste the fruit and plant some of the seeds.
We still had time to travel to the Arctic to see the Northern Lights.We used flashlights to shine light on a CD and a DVD to refract the white light and reveal the colors hidden inside. Click here to learn more about Aurora Borealis.