Evaluating Expressions Question Stack Activity

I'm piggybacking here off of a post from Sarah Carter.  I loved the question stack cards Sarah created for her students to practice evaluating expressions.  However, my eighth graders hadn't reviewed operations with integers yet, so I wanted a more basic set of cards that didn't include negative numbers so that I could check that my students had the process down for substitution and following the order of operations to evaluate.

Sarah does a great job explaining how the question stack works.  If you've never done a question stack before, what's important to note is that these are not flashcards!  The answer is NOT on the back of the question card.  You start by laying out all the cards answer-side up (this is your answer bank).  Flip one card over to reveal a question to start.  Find the answer somewhere in your answer bank and place that card question-side up on top of the last question card to create the "stack."  Answer this question next, flipping the next answer card on top of the stack to reveal another question.  This process continues until all the cards are question-side up in the stack.  The answer to the top question should be on the bottom of the stack if you flip it over.  If at any point you can't find an answer in your answer bank or you loop back to the first card in your stack without using all of the cards, you made a mistake somewhere.  As Sarah says, it's a great self-checking activity for students.

Basic Stack
These cards contain expressions that require one or two substitutions to evaluate.  There are no negative numbers and only basic operations (no absolute value, square roots, exponents, etc.).

 

Moderate Stack
These cards contain expressions that require more than two substitutions and/or are longer with more steps when evaluating.  This level contains exponents, but still no negatives, absolute value, or square roots.

 

Challenging Stack
I called Sarah's stack the challenging stack.  This stack requires students to evaluate expressions with negative numbers.  It also includes operations such as absolute value and square roots.  I hadn't yet reviewed this with my eighth graders this year, and I knew that I would have some students who remembered how to do this, but not all of them would.  Some students who were comfortable working with integers and other operations actually found this question stack easier than the moderate one because it didn't require as many steps to evaluate.

When I did this activity this year, I told my students that they would need to finish two question stacks in the class period.  I let them choose if they wanted to start with the basic or moderate stack, but I required that they complete at least one of those before attempting the challenging stack.  This was our first question stack of the year, so I wanted to make sure that at as they were getting started, I was available to answer questions about how the question stack works, rather than how to evaluate a more challenging expression.

Timing & Logistics
By the time I explained the activity and we got started, students had about 35-40 minutes left in class.  Most of my students were able to finish two question stacks (some even started the third) in that time.  Sometimes I have my students use whiteboards to complete the problems, but this time I had them show all their work on a separate piece of paper to turn in.  My classes are so big this year and I figured I would be answering a lot of questions about how the question stack works that I wasn't sure I'd be able to go around and see every student's work if I let them do it on whiteboards.

I also had my students work individually this time.  Sometimes I have them work with a partner, but evaluating expressions that don't contain negative numbers is definitely something my eighth graders should have learned before this year and I wanted to check that every student felt comfortable doing this.  As I told my students, part of what we do in eighth grade is work on notation, so even though I know you can do many of these problems in your head, I need to see that you know how to write down your work and show each step.

For this activity, I printed each level on a different color paper.  Other times when I have made question stacks, I'll print each set on a different color so that if students drop a card on the floor, they know who it belongs to based on the color of the card.

If you want to make your own question stack, definitely check out the template that Sarah shared in her post.  I can't tell you how many times I printed my own stack only to realize that my answers were in an order that did not create a loop!


View/Download: Evaluating Expression Question Stacks - Basic & Moderate Versions
(I reformatted these to make them easier to cut apart which is why they look slightly different than my pictures.)