## 2.20.2011

### Point Slope and Slope Practice

I've been trying to come up with more ideas where students solve problems with more than one step as well as a way for them to self-check and kind of monitor their own progress.

And now I would like to share them with you. :)

First of all, index cards are a teacher's best friend.

Second of all, I'm finishing up (*fingers crossed*) my linear equations unit and I used basically the same idea to practice two different concepts.

My first idea was to make two sets of cards, one with point-slope form equations and the other set with the same equations but in slope-intercept form.

The point was that the students with slope-intercept form cards would graph their equations on their handy dandy whiteboards. Then the other students who have point-slope form equations would solve them for slope-intercept form and then go find the student who has the matching graph.

The bad part of this idea was...I never actually did it. But aren't my cards pretty? =)

Idea number two was much better and actually implemented.

I took one set of cards and wrote two ordered pairs on the front.

Students were in partners. The first partner uses the slope formula and finds the slope between the two points. I wrote the answer on the back so tiny that they wouldn't see it through the card. The second partner flips the card over to make sure they have the correct slope.

If not, they go back and look for the mistake. If they are correct, the second partner now takes one of the points and the slope and writes the equation in point-slope form. Then, they solve the equation for slope-intercept form.

I had all the cards (there were more than this) laid out and the pair had to come up and find their equation.

If they couldn't find it, then they knew their equation was wrong (since they had already checked the slope).  And, from looking at the equations and their slope, they could usually pick out what their equation should be and that helped them to find their mistake.

Once students thought they had the matching pair, they flipped both cards over. In the top left hand corner I had written a tiny capital letter on each set. If the cards matched, students knew they were correct.

I gave them a new card of ordered pairs and the partners repeated the process, switching roles each time.

I hope this doesn't sound too complicated. It was somewhat confusing at first but after the first set of cards, students knew what to do. Of course, I was there to help them correct mistakes but my biggest job was to make sure students weren't just finding the letter and then searching for the right card. I kind of played gateway to the cards and made them tell me their equation or show me their work before getting to choose a card.  Like any other activity, teachers need to circulate the room, check and correct.

If this doesn't work for you, I hope it triggered some other idea of how to use index cards, get students up and moving around, or just to break up the monotony of your routines.

#### 3 comments:

1. I hope you don't mind, but I've added this to the "Virtual Library of Review Games" on my blog. I like that you have the students working in pairs and incorporating a couple self-checking features: very clever with the matching letters. If you wanted to have a day two, Miz T at Teaching Statistics has a nice game called "Gallery Walk" worth considering:

http://challenge-of-teaching-math.blogspot.com/2011/02/virtual-library-of-review-games.html

Thanks for sharing your lesson and sorry that your colorful cards went unused.

Paul Hawking
Blog:
The Challenge of Teaching Math
Latest post:
Posts I really like from (Math Be Brave)
http://challenge-of-teaching-math.blogspot.com/2011/02/posts-i-really-like-from-math-be-brave.html

2. Paul,
Thanks for your comments. I've already read MizT's blog post and I've seen the gallery work done in PD but not in the classroom. Seems like a good strategy to use for word problems so maybe I will use it to help students set up word problems when solving systems of equations.

3. Thanks for sharing the information and I am here to share some general information about the slope of a line, It is a measure of how much the line is inclined and is a number which indicates both the direction of the line and the steepness of the line.
Area of a Rectangle Formula