Out of Bounds

Objective

SWBAT represent constraints by equations or inequalities.

Big Idea

Find your limits, or at least find the limits to the equations and inequalities in an assortment of problems.

15 minutes

Put it into Action

35 minutes

I tell my students that they get to work with their front-partner to find the constraints for today's Limits Challenge problems.  I remind them that they each need to write their own responses but that they can definitely collaborate to figure out how to handle each challenge.  I also tell them to be ready to present at least one problem of my choosing to the class.  I pass out the Limits Challenge problem sheet and ask if there are any questions, then tell them they have about 20 minutes to complete the problems. (MP1, MP2, MP4) While my students are working I walk around offering encouragement and assistance as necessary.  For example, if a team is having trouble coming up with constraints, I might ask leading questions like "What is the lowest value that will work for x?" or "How are x and y related?"  As they finish up the challenge I have each team draw from a cup of numbered popsicle sticks to determine which problem they'll present.  I ask each team to present in order starting with problem #1 and have the rest of the class critique their method and solution.  The presenting team has an opportunity to respond, then the next team presents and so on until we've gone through all the problems. (MP3)

Wrap it Up

5 minutes

To reinforce the idea of constraints on equations and inequalities I give my students each a notecard and ask them to summarize what constraints they worked with for today's problems.  I explain that I don't want the details of each problem but instead am looking for a more general statement like, "most of the problems had values that couldn't be negative".  I explain the value of these notecards in my video.