|The Magical Minds||
For homework, the Magical Minds were asked to write and perform a short song using subtraction. At morning meeting we took a moment to listen to everyone's creation.
After introducing multiplication as equal groupings and skip counting, I introduce the Magical Minds to arrays with this fun video created by Mr. Salsich and his third graders.
While the video plays I ask the kids to predict how the kids will arrange the chairs for the sloth's presentation. We start using mathematical language of rows and columns.
Afterwards, I open a SmartBoard file asking the kids to arrange chairs for our classroom mascot, Kagunda the three-horned chameleon. And using their fingers to manipulate the pictures, the kids take turns creating different arrays. This is when I begin to introduce the language of factors and product.
Finally, when I can see that most students understand how to represent multiplication facts using arrays, I let them build their own arrays using anything they want from our classroom. This kinesthetic activity works as both a powerful assessment of their understanding as well as provides plenty of opportunity to address the needs of individuals.
After learning the Polygon Song during our class meeting, Mr. H invited the Magical Minds to create a list of the most common polygons. He started with a common definition of a polygon: "A shape having three or more straight sides." Then the students were asked to use the song to figure out the names of 5, 6, 7, 8, 9 and 10 sided polygons. We placed drawings around the room of the different kinds of shapes, and students did their best to draw these complex shapes.
Teachers have a rule about teaching with math manipulatives: Let the kids explore with the tool before asking them to use it for instructional purposes. This is the rationale behind our first lesson with unifix cubes.
As with most of our classroom materials, I introduce a new tool using the Guided Discovery method. The lesson begins with a mystery - a box wrapped in butcher paper and covered with stickers.
"What is it?" they beg to know. Inside my head I hear my teacher voice cackle with glee - they are already hooked.
After collecting several predictions of what might be in the box, we open it.
"Unifix Cubes!" they declare with excitement.
"Have you ever used these before?" I ask. Hands shoot up, and I start a poster full of their creative ways to use our new tool.
I give the Magical Minds 20 minutes to work with the manipulative, encouraging them to try something not even on the list. While they explore, Mr. H and I walk the room, documenting and recording their thinking.
We leave 15 minutes at the end of the lesson to reflect on our projects. The children use their improving presentation skills to share their projects.
Some kids tell stories with their cubes. For example, Ben built a house and Yasmeen built a castle with a moat. Zara, of course, has taken a more artistic approach and created a sunflower under a partially cloudy sky.
Luci has used a dry erase marker to write numerals on her cubes, which she fashions into a math game. Isa and Ellora created graphs. Ellora explains that hers might document how many people like different colors. Isa explains she is recording the value of different stocks, "This one is Apple, this one is Zynga..."
Wow! I haven't taught anything, but already we've learned so much from each other.
After taking a gallery walk around the room, I ask the Magical Minds to quickly estimate how many cubes they think they used in their project.
Then, while they count exactly how many cubes they used, Mr. H and I roam the room, listening to their counting skills and asking them to explain how they got their estimation. We are looking to see how their number sense is. Are their guesses reasonable? Can they count what comes after 59?
The children want to know when they can do it again.
As we learn more about place value, we are using abacuses to help. Abacuses have been used by mathematicians around the globe for centuries to help with counting. Last week Ed told me that he would help the Magical Minds and me build our own abacuses. Before we could build them, however, we had to show Ed that we know how to use them. Thus, we began with paper and plastic markers (circles or cubes).
The best part about Roman Numerals? Its like a code. Codes are cool. You know what else is cool? Invisible ink. Even better...chemical reactions.
It all began with a math puzzle. During snack, each Magical Mind was give a number, written out. For example, nine hundred and nine. Their task was to figure out how to write the number with digits. For example, 909.
There were four numbers, and after snack I asked the kids with the same numbers to form teams. They worked together to write their numbers, and then I gave them a challenge. "Work with your team to write the Roman Numeral for your number."
Now for the invisible ink. I wet a paintbrush in some brown liquid and painted a white piece of paper. The liquid turned the paper a shade of bluish-purple, except where I had secretly written a Roman Numeral.
Each team received a small vial of "mystery liquid" to write/paint their Roman Numerals. They worked with each other to share materials and write their numbers.
After setting our hidden messages aside to dry, we took a short break to clear our minds. I needed them to shift their minds from thinking mathematically to thinking scientifically.
The invisible ink works because of a chemical reaction. In order to help the Magical Minds understand what a chemical reaction is, I invited them to participate in a science experiment with Alka-Seltzer and baking soda.
Each team got a set of four test tubes filled with clear liquid. I informed them there were only two different kinds of liquids and asked them to use their senses to determine what the liquids were.
With some investigation the Magical Minds quickly discovered the test tubes held either water ("pool water" was the most common response) or vinegar.
Each team was given a small piece of Alka-Seltzer and instructed to place half of the tablet in each liquid and observe the reaction, if there is one. I let them know that if they see a change in the liquid or a change in the Alka-Seltzer they would know it was a chemical reaction. After watching the bubbling and fizzing, the kids agreed that the Alka-Seltzer reacted with both liquids, but it had a stronger reaction in the water.
Next, each team was given a small vial with baking soda. I asked them to test 1/8 tsp in each remaining test tubes and look for chemical reactions. As you may have predicted the Magical Minds detected no chemical reaction when they added baking soda to water, but were giggly and excited when they witnessed the foaming reaction between baking soda and vinegar.
Armed with a burgeoning understanding of chemical reactions, the Magical Minds returned to the invisible ink. I demonstrated how I added iodine to water to create the brown-ish liquid. "Paint the iodine water on top of the invisible ink and look for a chemical reaction."
What do you think? Does the iodine react with the lemon juice?
About the Author
Erin Mahollitz is an international teacher teaching 2nd Grade in San Francisco, CA.
She specializes in inquiry-based instruction, technology integration and social & emotional education.
This website is a collection of stories, ideas, resources and lessons from Erin's classrooms.
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