Balance Scale Equalities and Inequalities

I know it sounds absurd, but no matter what age your child or student is (if they are old enough to be in school and doing math), you should be using the words "equality" and "inequality" to describe numbers that are equal or not equal. One simple way of doing this is to use a pan balance. You can differentiate these activities to use with students in K-8!

My students are regrouping when adding or subtracting 2 and 3-digit numbers. In order to help them understand that regrouping is not taking away or adding any numbers, but simply putting them in another place and form, I do something like this:

If you counted, you'd see ten cubes on one side and a rod (made of ten connected cubes) on the other side. The arrow points to the middle because the scale is balanced! 

To show greater than and less than, all you have to do is have the children count out the number of cubes and / or rods (or flats if you're working with hundreds) and see which side is heavier (goes down).

You can also do this with "missing number" or pre-algebra problems. Using the above picture, I would write a missing number sentence: 5 + __ = 10. Students would add cubes to the higher side (meaning that side of the scale is lighter, and thus represents a smaller number) until the balance showed both pans being equal. They would be able to find that 5+5=10. No more frustration, and no need to show students that they can use the inverse (10-5=___) to find the answer!

You can try this without having a pan balance or base-ten blocks / place value blocks at home...because I have found the websites for you! 

This site is called the Illuminations Pan Balance and it was created by the National Council of Teachers of Mathematics. You can start out by showing students how different shapes (instead of numbers) can have different masses. Therefore, the square is greater than / heavier than the triangle. I have used this with kindergarteners and they understand it! I used to have a worksheet that was made specifically for this site, but can't find it at the moment.

Next, you can show them that they have to add to the side that weighs less to balance it.

Students can reset the balance or complete different "sets" where the shapes have different masses OR you can have them try it with numbers.

As you can see, we just demonstrated the commutative property of addition - the order of the addends doesn't change the sum. We created an equality!

Now we've used the associative property of addition! 

Download some practice sheets here! This document is a pdf that includes harder problems and blank scales for students to create their own equalities.

Check out my other Making Math Memorable Posts!

Baby It's Cold Outside!

...not really! It's been about 65 degrees or warmer the last few days, which is about 20 or more degrees than our average -not your typical NJ November!

On to the topic of this post: teaching about warm and cold bloodedness!

This is another one of those science topics that I always got frustrated with because all I could really do was have my students make predictions and then have them do research or tell them which animal groups were cold-blooded and which were warm-blooded. There really wasn't anything past the knowledge part of Bloom's Taxonomy, and certainly no inquiry. I wanted my students to at least be able to explain how scientists prove how they know which animals have body temperatures that remain constant or change temperature according to their environment.

First I read The Magic School Bus Gets Cold Feet  to my students. They began to form a definition of what the two terms meant, which animals were cold-blooded, and which were warm-blooded. We used the Scholastic lesson plan and lab sheet that went along with the book. Click here to download it.

Then I came across The Infared Zoo at Cool Cosmos, a website created by the California Institute of Technology. It shows students infared images of different animals taken at a teaching zoo. These pictures show a lizard - and how its body temperature has changed over time. Students use the color key to determine an estimate of the body temperature of the animal and discuss why they think each part would be warmer or colder, or what could cause an animal's temperature to drop or rise rather than staying constant.

Click the logo to visit the site!

Check out lesson plans that go with the site!

Check out my animal classification post here.

Animal Classification

Most of the time, when we teach children how to classify animals, we talk about their body coverings. But there's so much more to it than that! I found this great site that teaches students how to tell the difference between animal classes (resist the urge to say "Groups") and also gives them a fun computer game to play. It's also interactive board-friendly so I put it up on my Promethean Board. Please note that the site only covers animals that are vertebrates. Enjoy! 

Click here or on the picture to play the Animal Classification Game!

Check out other animal websites that I have compiled.

Check out my post on classifying animals as vertebrates and invertebrates!

What's inside animals?

Teaching Kids about Vertebrates and Invertebrates

I just had to share this great product that I came across last year while teaching science lab. I always struggled with how to teach students to identify animals as vertebrates or invertebrates. I wanted to go past the knowledge part of Bloom's so that kids knew more than just the difference between the two and the purpose for backbones. I found a product called What's Inside Animals?

It's available in a lot of places, including Amazon. I got mine for about $30, but right now they are on sale. All students have to do is hold a card with the picture facing them and the back facing a light source. They can see a backbone through the picture! Here are some pictures of my students using them:

I found that they work best when you use a flashlight shined behind them in a dark room, but you can also hold them up to a ceiling light source!

I also use www.eskeletons.org, a site from the University of Texas at Austin. It allows students to compare skeletons of mammals while learning about animal classification. It can also be used in an evolution discussion.

The vocabulary is advanced, but trust me I did this with second and third graders and they loved it! They were able to compare and contrast the bones and started naming the body parts!

Check out another post on dinosaur bones and fossils here.

The Harvest Birds

One of our upcoming reading stories is called The Harvest Birds.

The story is about Juan Zanate, the youngest of three Mexican boys in a family. When Juan's father dies, he leaves his land to his two eldest sons. Juan gets his turn to work a small piece of land given to him by an old man in town, and becomes much more successful than his brothers with the help of zanate birds. Juan learns a lesson of patience, hard work, and the importance of working with nature as he makes his dream of becoming a farmer and land owner come true. 

video of a zanate bird

In celebration of the harvest, we created these scarecrow glyphs. Students had to color according to the directions and we soon found that no two scarecrows were identical, just as no two students are exactly the same! I used a scarecrow and fake fall leaves for the bulletin board border.

Download a glyph with a scarecrow pattern and directions here. Download glyphs here or here.

For more Harvest Birds Activities, check out my class website!