Camera Case & Pads of Paper Weigh In

How much does the camera case weigh?

Ontario Grade Levels:
Common Core Grade Levels:

Shared By:
Justin Levack
Kyle Pearce

Math Topic:
Partial variation, initial value and the rate of change of linear relations, finding the equation of a line given two points.

Ontario Curriculum Alignment:

Common Core State Standard Alignment:

Camera Case & Pads of Paper Weigh In 3 Act Math Task Resources

Grab all the videos/images by clicking download below:

Download Task

3 Act Math With Partial Variation Linear Relations

Here’s another task that is a good next step once you’ve tackled the Tech Weigh In 3 act math task that covers direct and partial variation linear relations. This task gives students another chance to get some exposure to partial variation linear relations and could provide an opportunity for the teacher to begin consolidating the topic by moving towards some more abstract concepts like the slope formula and finding linear equations given two points. Similar tasks to check out would be Stacking Paper, Stacking Paper Sequel and Thick Stacks.

Special thanks to Justin Levack again for coming up with the “weigh in” idea and pushing me to actually record this with him when we are all running out of steam at the end of the school year.

Act 1 – Introduce the Problem

As stated above, I’d suggest tackling the Tech Weigh In 3 act math task prior to doing this task. Because I would do Tech Weigh In first, I feel that an act 1 is not really necessary for this particular problem. Tech Weigh In sets the stage nicely and this is more of a sequel than anything else. This photo would likely take care of it:

Camera Case & Pads of Paper Weigh In 3 Act Math Task

What’s the question?

As always, get your students talking about what they think this math task is going to focus on. Writing the questions out is always helpful. In this case, since they’ve already done Tech Weigh In, my students are pretty confident we’re going to be finding out how much the camera case weighs (or initial value). However, I use this task to get a bit more specific and focus on questions along these lines:

  • How much does the camera case weigh and what do we call this number? (i.e.: initial value)
  • How much does each pad of paper weigh and what do we call this number? (i.e.: slope/rate of change)
  • What is an equation that could represent this linear relation?
  • What would the weight be if we stacked _____ pads of paper?
  • How many pads of paper would it take to get a weight of ____?

Making predictions is always a good practice after some questions have been shared out.

Act 2 – Giving Some Information

Show your students this:

Camera Case and Pads of Paper Weigh In - What's the Weight of the Camera Case?

Act 3 – Watch the Solution


Here’s two exemplars of how students may approach this through an inquiry approach:

Camera Case and Pads of Paper Weigh In Exemplar 1 - Table of Values

Camera Case and Pads of Paper Weigh In Exemplar 2 - Visual Inquiry Approach

Many teachers might consider using a procedure to find the equation of a line given two points using the slope formula as the next logical step. However, I have witnessed a few students essentially use substitution to solve this type of problem. It might not look as organized as how students are instructed to solve a system of linear equations, but the thinking is much the same. Here’s an example of what it might look like (but this is probably too organized for a real case):

Camera Case and Pads of Paper Weigh In Exemplar 3 - Simple System of Equations

I’d suggest that after solving a simple system of equations using substitution, you might want to move towards consolidating the exemplars above to the slope formula and solving y = mx + b algebraically for the initial value, b:

Camera Case and Pads of Paper Weigh In Exemplar 4 - Finding Equation Given Two Points

Access Resources

Check out all of the resources here. Or, you can grab what you want individually below:

Student Exemplars

Be sure to share your student exemplars in the comments!

Have you tried the task? Let us know how to make it better in the comments!

Download Resources For This Math Task

Click on the button below to grab all the media files for use in your own classroom:

Download Task

Search 3 Act Math Tasks By:

Previous/Next 3 Act Math Tasks In The Repository

Or, see the complete directory of real world math problems.


Search 3 Act Math and Real World Math Tasks

Search By Ontario Curriculum Expectations

Ontario Curriculum for Math Grade 9, 10

Share Your 3 Act Math & Real World Math Tasks

If you have been creating some innovative real world math tasks, submit them to appear in our list by completing a simple form.

| Privacy Policy | Sitemap

%d bloggers like this: