Friday, August 23, 2013

Comparing Real Numbers

I have noticed in the past that there are some students in algebra who can't set up the real number line correctly.  With that, I have noticed that placing numbers on a real number line is challenging for some students as well. 

For the lesson that reviews ordering and comparing real numbers, I was thinking that it would be a good idea to make a number line and do some ordering of real numbers.  I wanted something that would be compact and fit into the ISN. 

I thought about using a piece of paper folded in half because I liked the idea that zero would be on the fold and in the middle of the line.  From there it was just a matter of putting positive and negative numbers on the number line.  I also added tick marks for every tenth.  I thought that this would help to place the numbers more accurately.

I then used some colored dot stickers cut in half to mark the position of two sets of numbers on the number line.  The stickers were a bit too big, but ultimately did the job.  I just made sure that the straight cut lined up with the numbers position on the number line. 

The lesson also deals with adding and subtracting real numbers.  I layered some sticky notes so that I could highlight two things:
1) The procedure the book uses for adding and subtracting real numbers with mixed signs, and
2) Reminders about fractions needing the same denominator and about lining up the decimal points.

I have been finding a lot of uses for sticky notes in the ISNs that I am trying to put together for the students.  (I hope I'm not alone in saying that I use sticky notes for everything and could probably join a 12 step program if one existed.)  I have been using them to highlight steps in procedures and to save space by layering ideas similar to the picture at the left.  Does anyone have other ways that they use sticky notes in their ISNs?


  1. I like your number line idea. I am always looking for ways to make my students' ISNs more interactive that will aid in understanding. I have a large interactive number line in my room, but having one in their notebooks should help.