Matrices Day 1

1
Matrices (Day 1)

• Ms. Lenk
• Foundations of Algebra
• Fall 2009

2
Matrix Uses

• Data is often _____________ in a
  __________________ or _________________. For
  example, the data in the table below tells how
  many of two types of sneakers were sold in three
  stores in the Sneaker Shack chain.
• By __________________ labels from a ___________
  or ____________ and keeping the ___________
  organized the same way, you can create a
  _____________.

displayed
table
spreadsheet
removing
table
spreadsheet
numbers
matrix
3
Vocabulary
a rectangular array of numbers

• Matrix
•  Element or Entry
•  Dimensions
• Rows
• Columns
• Square Matrix

each number in a matrix.
the of rows and columns in a matrix.
always horizontal
always vertical
a matrix with the same number of rows and columns.
4
Example 1

• An electronic store sells three models of LCD
  Televisions at each of three stores. The table
  below shows how may of each model LCD televisions
  were sold in the stores during June.
•  
•  
• How would you represent this data in a matrix?
  What dimensions would the matrix have?

This matrix is a square 3-by-3 matrix.
5
Example 2

• The matrix below shows how many of each model LCD
  televisions were sold by the same stores as in
  Example 1 during the next month of July.
• How many more of Brand C did Store A sell than
  Store C in the month of July?
• You can make _____________ of data between two or
  more _____________. You must, however, be
  careful that the two ____________ are set up so
  that the __________ _______________ properly.

Electronics Express Store A sold 13 more Brand C
LCD televisions than Store C.
comparisons
matrices
matrices
data
corresponds
6
Example 3

• The two matrices for June and July sales of LCD
  Televisions sold at the three stores are shown
  side-by-side below.
•  
• How many more of Brand B did Store B sell in June
  than in July?

Store B sold 14 more Brand B LCD televisions in
June than in July.
7
On Your Own

• The table below shows the number of students that
  belong to the Science Club at Monroe High School
  by year and gender at the beginning of 2005.
• Thinking it Through 
• Based on the table, how many rows will the
  matrix have? _____________________________
• Based on the table, how many columns will the
  matrix have? __________________________
• Write the Matrix below

4 rows
2 columns
This is a 4 X 2 matrix. (4 rows, 2 columns)
8
Partner Activity

• Listen to ALL directions before moving.
• Your group will get an activity sheet with a
  problem to solve on it.
• Together, solve the problem. Show ALL your work
  and use complete sentences to answer the
  question. Make sure you draw all matrices!
• Turn in the activity sheet for a grade. Make sure
  BOTH of your names are on the sheet.
• Get with your 6 oclock buddy and get an activity
  sheet for your group.

9
Homework

• Assignment 10
• Worksheet Matrices Day 1
• If I have not told you your current homework
  grade, you may ask me before you leave.
• Dont forget that homework counts as 25 of your
  grade! Dont let homework be the reason you fail!