Author David Graser, Yavapai College, Prescott, AZ (


This contrived project is based on a problem from Harshbarger and Yocco’s College Algebra textbook. As with other projects, students use the letters in their own name to customize the project. They are given information about sources of nutrients in dog biscuits and the amounts of each source in the different types of biscuits. Using this information, students formulate matrices and then multiply them to total amount of each nutrient in the different types of biscuits.

  • Content Area – College Algebra, Finite Mathematics
  • Time Frame – 1 to 2 weeks
  • Published – Sept. 10, 2008
  • Keywords – matrix multiplication

Project Content

Project Letter (DOC | PDF)

Scaffolding Resource

Matrix Multiplication on a TI Graphing Calculator (PDF)

Matrix Multiplication in Excel 2003 (PDF)

Matrix Multiplication in Excel 2007 (PDF)

Matrix Multiplication (Video)


  • Students often have a hard time discovering how the matrices should be labeled and using those labels, how the product should be labeled.
  • This project could easily be changed to any set of products and sources of the materials used to construct those products. You can see one possibility in the video above.

Your Questions Answered