I wrote this worksheet to make sure that my algebra students could properly solve equations involving absolute value.
I previously teach them to use the "order of operations ladder" of inverse operations to solve equations, so to "undo" the absolute value, I have them write two separate equations.
For instance, if they are solving | 2x + 3 | = 7,
I have them write two equations:
2x + 3 = +7 or 2x + 3 = –7
and then they solve those.
Despite my best efforts, I still have students who simply ignore the absolute value bars and just carry on, so they often get only one of two solutions. I give them only one point out of 7 for such responses (5 points + 2 points for checking all solutions in the original equation), and I also have found a gimmicky analogy that they seem to remember:
When it's time to solve | 2x + 3 | = 7, I tell them to look at the absolute value bars as ribs, and "rip the guts out" from between the ribs. If they have x-ray vision, I tell them, they can "see" that the stuff inside the bars (the guts) must equal 7 or –7. There is no pedagogical reason to teach it this way, and it's a rotten analogy in terms of mathematical understanding, yet it works about the best I've ever seen for solving this type of equation, so I go with it.
If any of you have a better analogy or explanation that yields better results, please share it!
I use this activity within cooperative groups, and I circulate to make sure they are getting the purpose of the questions.
The file includes spiral review problems.
I have students put their work on a separate sheet of graph paper.
Please download the pdf preview file first, so you can see exactly what's included; the product file is a word document, which you may personalize for your students.
Immediately before this worksheet, I use the worksheet named 'Absolute Value Part 1 Fall 2013' (http://www.teacherspayteachers.com/Product/Absolute-Value-Part-1-Fall-2013-1092906
), and immediately after this worksheet, I use the assessment named 'Algebra 1 Group Practice Test Introductory Material Fall 2013' (http://www.teacherspayteachers.com/Product/Algebra-1-Group-Practice-Test-Introductory-Material-Fall-2013-1105853