1. Unit 2: What is a matrix – really?
Learning Target: I will organize information using matrices, give dimensions of a matrix and identify elements of a matrix.
Homework: Organizing Data into Matrices Worksheet
Unit 2: What is a matrix – really?
Sec 1: Organizing Data into Matrices

2. What do you think a matrix is?

3. Definition
Matrix (plural: matrices) – a rectangular array of numbers written within brackets.

4. Things you can do with a matrix
Organize Information
Add, Subtract and Multiply to find quantities quickly with large groups of information.
Find missing quantities
Solve systems of equations
Transform geometric figures: rotate, reflect, translate

5. Ex 1: Dimensions
The number of horizontal rows and vertical columns determine the dimensions of a matrix
State the dimensions of each matrix.
A B C.
−3 −
− −3

6. Ex 2: Identifying a Matrix Element
Find each of the following elements:
𝒂 𝟑𝟏 𝒂 𝟐𝟐 𝒂 𝟐𝟏 𝒂 𝟏𝟏

7. Ex 3: organizing data
Energy is often measured in British Thermal Units (Btu).
Write a 3 x 2 matrix to represent the data above.
Rewrite the information as a 2 x 3 matrix.

8. Ex 4: Gymnastics Write a matrix W to represent the information.
Floor Exercise
Vault
Balance Beam
Uneven Bars
Amy Chow
9.525
9.468
9.625
9.400
Dominique Dawes
9.087
9.393
8.600
9.675
Kristin Maloney
9.225
9.312
9.575
Elise Ray
9.687
Write a matrix W to represent the information.
b. What are the dimensions of the matrix?
c. Which element represents Kristin Maloney’s score on the vault?

9. homework
Organizing Data into Matrices Worksheet