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STEM pattern

STEM pattern

December Math Task

December Rich Math Task

Unit Dog

This activity will allow students of all abilities to engage, collaborate, problem solve and contribute toward deeper mathematical understanding of dimensional mathematics while engaging in a hands-on and rigorous task.


This activity comes from the National Math and Science Foundation and involves hands-on experimentation to help students better understand surface area, volume, nets, ratios and proportions.

Grade Level:

This activity is designed for 6th and 7th grade students, but can easily be scaffolded for upper elementary students.


  • Determine the surface area and volume of an irregularly shaped object
  • Draw front, side and top views of the object
  • Create nets for various parts of the object
  • Apply scale factors to the nets
  • Build models with unit cubes and with cardstock nets
  • Investigate the resulting effects on surface area and volume when dimensions of a shape change proportionally.


In this activity, students will explore the connections between linear measurements, area and volume of three dimensional objects.  Students will create a “unit dog” out of connecting blocks and then discover what results when the dimensions of the unit dog are increased.  Students will predict, discover and confirm connections between 1-dimensional measurements, 2-dimensional measurements and 3-dimensional measurements.  Students will also have an opportunity to create nets from 3-dimensional objects and work with ratios/proportions while problem solving.

Mathematical Process Standards (Common Core):

MP3:  Describe and justify mathematical understandings by constructing viable arguments, critiquing the reasoning of others and engaging in meaningful mathematics discourse

MP5: Use appropriate tools strategically.

MP8:  Look for and express regularity in repeated reasoning.


The activity contains detailed teacher instructions as well as teaching strategies and notes to help teachers prepare for students struggles and scaffolding approaches.  The activity also contains the student packets, the completed solutions and the printable grid paper to use during the activity.

This activity is extremely rich and flexible.  The full activity could be done over multiple class periods or it can easily be scaled down to target specific standards in one class period.

Download the full activity description from NMSI as a PDF here.



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