Tuesday's tip

Dear mysterious visitors,

Over the coming weeks, I am on a mission to teach grade 9 students how to manipulate Linear inequalities in one variable. None of the textbooks I normally refer to for good ideas and strategies are very eloquent on the subject so I thought I would ask the maths blogging community for some help.
I was thinking of setting up some activities for the students to get a feel of what inequalities are all about and why the rules we learn apply to this and that case but I don't really know where to start.

I've searched the internet, without much success so far. However, I've come across this on how2teachmath.com:

"The way I like to do this is to give students inequalities and then have them check 10 to 15 points. I then have them plot the true points in one color and the false in another. Eventually the students will begin to see the pattern. This is a very good activity to be done in cooperative groups. It can also be done by giving the students a range and asking them to find 5 true and 5 false points. This gives the students more sense of ownership in the problem and can lead to them developing their own way to solve the problem."

What do you think about this approach? Have you ever tried it out with your kids? Your suggestions would be much appreciated.

Have a lovely day,

*M*