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Operations with Matrices. Dan Teague NC School of Science and Mathematics teague@ncssm.edu. Reasoning and Sense-Making. One key is to find a way of introducing new material that fits into the jigsaw puzzle created by what is already understood. Working with Units.
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Operations with Matrices Dan Teague NC School of Science and Mathematics teague@ncssm.edu
Reasoning and Sense-Making One key is to find a way of introducing new material that fits into the jigsaw puzzle created by what is already understood. http://courses.ncssm.edu/math/talks/conferences/
Working with Units If you are walking 2 miles per hour, how fast are you traveling in feet per hour? We know there are 5,280 feet in a mile, so http://courses.ncssm.edu/math/talks/conferences/
If you are walking 2 miles per hour, how fast are you traveling in miles per minute? We know there are 60 minutes in an hour, so http://courses.ncssm.edu/math/talks/conferences/
Think about the Mathematical Practices http://courses.ncssm.edu/math/talks/conferences/
Now, on to Matrices http://courses.ncssm.edu/math/talks/conferences/
What is a Matrix? A matrix is a rectangular array of numbers. A matrix as a model is a rectangular array of numbers with meaning. http://courses.ncssm.edu/math/talks/conferences/
The Summer Woodworking Project You and a Partner make 3 kinds of cutting boards: Type I: alternating Oak and Walnut Strips Type II: alternating Oak, Walnut, Cherry Strips Type III: checkerboard pattern of Walnut and Cherry http://courses.ncssm.edu/math/talks/conferences/
Creating a Matrix During weekends in the month of April, you constructed 5 Type I, 8 Type II, and 3 Type III cutting boards. Your partner constructed 6 Type I, 4 Type II, and 10 Type III cutting boards. http://courses.ncssm.edu/math/talks/conferences/
April and May Results Dimensions of the Matrices Interpretation of the Elements http://courses.ncssm.edu/math/talks/conferences/
How many type II’s did your partner make in the 2 months? How many type I’s did you make in the 2 months? Can you create a matrix representing the work done by each person during the 2 months? http://courses.ncssm.edu/math/talks/conferences/
Define this process as Addition Notice the order. We didn’t define addition then practice. We asked what made sense, and used that for our definition. http://courses.ncssm.edu/math/talks/conferences/
How many of each type did the partners make during June? http://courses.ncssm.edu/math/talks/conferences/
Now We Can Define Subtraction http://courses.ncssm.edu/math/talks/conferences/
Next Spring you want to Doubled your April Output http://courses.ncssm.edu/math/talks/conferences/
Types and Wood Interpret the elements in the Wood matrix. http://courses.ncssm.edu/math/talks/conferences/
In April, how much Oak did You use? In April, how much Cherry did the Partner use? http://courses.ncssm.edu/math/talks/conferences/
Define Matrix Multiplication Just like (ft/mile)∙(miles/hr) = ft/hr http://courses.ncssm.edu/math/talks/conferences/
Cost Matrix Each strip of Oak costs 2 cents. Each strip of Walnut costs 4 cents. Each strip of Cherry costs 5 cents. What is the cost of the wood used by each person? http://courses.ncssm.edu/math/talks/conferences/
Cost Matrix Oak costs 2 cents/strip, Walnut costs 4 cents/strip, Cherry costs 5 cents/strip. http://courses.ncssm.edu/math/talks/conferences/ Just like (ft/mile)∙(miles/hr) = ft/hr
One key is to find a way of introducing new material that fits into the jigsaw puzzle created by what is already understood. http://courses.ncssm.edu/math/talks/conferences/
A mouse is placed in the maze above. It is equally likely to pass through any open door. Each time it passes through a doorway is considered a transition. What is the probability that the mouse will be in Room 4 after 2 transitions if it starts in Room 1?
Transition Matrix http://courses.ncssm.edu/math/talks/conferences/
What is the probability that the mouse will be in Room 4 after 2 transitions if it starts in Room 1?
From 1 to 2 and then from 2 to 4 Or From 1 to 3 and then from 3 to 4
Can we create a transition matrix for the two-step probailities? http://courses.ncssm.edu/math/talks/conferences/
Age Specific Growth http://courses.ncssm.edu/math/talks/conferences/
Begin with [ 100 100 0 0 0 0 0 ] sheep. How many sheep are in the [2, 4) age group in two years? How many in the [6, 8) age group in two years? How many in the [0, 2) age group? http://courses.ncssm.edu/math/talks/conferences/
Photo by John Haslam http://courses.ncssm.edu/math/talks/conferences/
After one transition, how many sheep in each group? After two transitions? http://courses.ncssm.edu/math/talks/conferences/
Matrix Multiplication http://courses.ncssm.edu/math/talks/conferences/
Calculator http://courses.ncssm.edu/math/talks/conferences/
Markov Chains http://courses.ncssm.edu/math/talks/conferences/
Operations with Matrices Dan Teague NC School of Science and Mathematics teague@ncssm.edu
What is the probability that a taxi from Downtown will be again in Downtown after three fares? http://courses.ncssm.edu/math/talks/conferences/