Algebra 1 Common Core Student Edition, Grade 8-9

Organizing Data

Using M at rices

Common Core State Standards

Pr ep ar es f o r N- VM .C.6 Use m at rices t o rep resent and

manipulate data, e.g., to represent payoffs or incidence

relationships in a network.

MP 1, MP 3, MP 4, MP 6

Object ives To organize data in a matrix

To add and subtract matrices and multiply a matrix by a scalar

They need a more

organized system

to keep track of

their hours. What

would help?

MAtHEMAIICAL

PRACTI CES

Lesso n

Vocabulary

• matrix
  elem ent
  scal ar
  scal ar
  multiplication

A matrix is a rectangular arrangement of numbers in rows and columns. The plural of

matrix is matrices (pronounced MAY truh seez). The matrix below shows the hours Jeff,

Tina, and Eric worked on Saturday.

Og awas Bakers

Jef f

Ti na

Er i c

5

2

3

t

Co l u m n

Ro w

You identify the size of a matrix by the number of rows and the number of columns. The

matrix above has 3 rows and 2 columns, so it is a 3 X 2 matrix.

Each number in a matrix is an elem ent. Matrices are equal if they are the same size and

the elements in corresponding positions are equal.

-1 (^2) -> 1
4 0_ (5 -1 ) 0
Esse n t i a l U n d e r st a n d i n g You can use matrices to organize data. This may make
it easier to perform calculations on the data.
726 Ch a p t e r 12 Data Analysis and Probability
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