You Want Me to Do What to That Matrix?

Learning Resource Type

Learning Activity

Subject Area

Mathematics

Grade(s)

9, 10, 11, 12

Overview

This learning activity will be used to introduce scalar multiplication and is intended for a Before Activity. The students will watch the Scalar Multiplication video to learn how to multiply a scalar into matrices. This activity will lead to learning how to add, subtract, and multiply scalar matrices with appropriate dimensions.

This activity was created as a result of the ALEX Resource Development Summit.

Phase

Before/Engage
Mathematics (2019) Grade(s): 09-12 - Algebra II with Statistics

MA19.A2.3

Multiply matrices by scalars to produce new matrices.

UP:MA19.A2.3

Vocabulary

  • Scalars

Knowledge

Students know:

  • The aspects of a matrix with regard to entries, rows, columns, dimensions, elements, and subscript notations.

Skills

Students are able to:

  • Write percents as decimals.
  • Increase or decrease an amount by multiplying by a percent (i.e., increase of 10% would multiply by 1.1).

Understanding

Students understand:

  • Multiplying a matrix by a scalar affects every element in the matrix equally.
  • Scalar multiplication is a tool that allows all elements of a matrix to be changed in a simple manner.

Body

  1. Multiply matrices by scalars to produce new matrices.

Learning Objectives

Students will be able to multiply matrices by scalars to produce new matrices.

Activity Details

  • This activity will be used at the beginning of a scalar multiplication lesson. 
  • The students will watch the Scalar Multiplication video to introduce matrices multiplication (this can be done as a whole group or assigned through Google Classroom).  
  • After the completion of the video, the teacher should display the Scalar Multiplication Practice and have the students work the problems.  
  • The teacher will circulate around the room to check for understanding of scalar multiplication.
  • Once the teacher has verified students’ understanding of scalar multiplication, he/she should teach students how to add, subtract, and multiply scalar matrices with appropriate dimensions.

Assessment Strategies

  • The students should write their answers to the Scalar Multiplication Practice in their math journals or on a sheet of paper.  
  • The teacher will assess the students by checking their responses and can correct mistakes or misunderstandings.

Variation Tips

The Scalar Multiplication video and Scalar Multiplication Practice could be assigned through Google Classroom.

Background / Preparation

Students will need to know about the dimensions of matrices.

Students will need their journals or a piece of paper to complete the Scalar Multiplication Practice.

The teacher will need to make sure there is an Internet connection (WiFi) and devices to use if he/she chooses to assign the video and practice through Google Classroom.

Total Duration

16 to 30 Minutes
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