Graphing Inequalities

In my Algebra 1 class, we have just started working with inequalities. I actually got some really good lesson ideas from Sarah Hagan at the Math = Love blog. I used a lot of her material for my own lesson, and to put in our own Interactive Notebooks. One thing, though, is that I didn’t realize she had PDF copies to download. I spent forever trying to make a foldable to copy hers. I think that I finally got the hang out of it, but it would have been way easier if I hadn’t spent all that time trying to create a similar one, only to find out that I could download her’s right at the bottom!

One thing that we are really working on is graphing the solution set for inequalities. I started to put meaning to it that I had never learned before. I was taught to memorize that we use an open circle unless it has the ‘or equal to’ part, then we use the closed circle. My students seem to be trying to memorize it this way, also, but I have been really trying to help them to understand why that is. When we are graphing the inequalities, we circle the number that we are given. So, we have been starting with the open circle every single time. Then, we shade in all of the numbers that are possible solutions. We first start by checking the number itself. When we have the ‘or equal to’ along with our inequality symbol, then we shade in that number, because it is included in the solution set. Every time one of the students says “So we up the closed circle when its ‘or equal to’ and the open circle the rest of the time,” I agree with them, but then I make them explain why that is.

It seems like it has been working well for my students. Hopefully, this unit goes great after we just spent the whole first quarter on solving equations! This is so similar, it should be a good confidence booster for the students, as well!

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