Grade 4 Lesson 1: Introduction to

Solving Inequalities

(Approximately: 2- 60 minute lessons)

Click Here: Printable Lesson Plan

On a computer? Click "file" then "make a copy" to save and make changes.

On an iPad? Select the 3 dots in the top right hand corner. "Share and Export" then "Make a Copy".

Content

Expectations:

Algebra

C2.3: Solve inequalities that involve addition and subtraction of whole numbers up to 20, and verify and graph the solutions

Big Idea:

In this lesson, to the best of their ability, students will learn to think critically and creatively and use positive motivation and perseverance. They will apply strategies such as: using an iterative approach by trying out different methods, including guessing and checking to promote problem solving. They will be making connections, evaluating choices, reflecting on and assessing strategies.

Learning Goals

We want students to understand...

What an inequality is.
How to solve an inequality
How to verify it is correct.
How to show the expression on a number line.

Success Criteria

I understand that any single algebraic expression describes many situations.
I understand what an inequality is.
I can test variables to prove the inequality true or false.
I understand how to put the expression on a number line.
I understand how to graph the expression on a number line.

teacher background

Variables-symbols used to represent unknown and/or varying values are used in expressions. An expression is something like m + 5, which indicates that 5 is added to a number (m), no matter what the number m is. Students must learn how to recognize that “n -10” means “take 10 from the value of n” as compared to “10- n" which means “how much less n is than 10”.
They must recognize that any single algebraic expression describes many situations. For example, m + 5 > 10 describes a multitude of situations and how to express it on a number line.
Graphs are effective models for describing relationships between various variables and quantities.
Source: Adapted from: Small, M. (2013) Making Math Meaningful to Canadian Students, K-8. Nelson Education (pp.620-621)

Prior Knowledge

Understanding Variables

Find out if your students understand variables, variables changing quantities, unknown quantities, writing expressions using variables and determining the number missing in addition and subtraction equations.
Knowledge Hook Mission

Pedagogy

Minds On

Source: https://www.mathsisfun.com/algebra/inequality.html

1)Review the symbols <, >, =

2)Provide students with the following minds on task: https://docs.google.com/document/d/1vglUaInRFihjoZ-fGQb7osq-KEhafHSjTuVrsYrq6_k/edit?usp=sharing

Additional Activity: Introduction to Inequalities: Number Talks: Minilessons for Extending Addition and Subtraction: “Money Model: Equivalence, Variation” Pg. 63 (need Canadian Coins and some foreign coins)

Action!

Source: https://www.mathsisfun.com/algebra/inequality.html

Teacher directed: a) Discuss what inequalities are: Inequality tells us about the relative size of two values. Mathematics is not always about "equals", sometimes we only know that something is greater or less than.
b) Look back at their inequality statements for the minds on diagnostic activity. Are they correct? Did they use the less than symbol? What did they determine for greater than inequality statements?
c) Discuss “greater than and equal to” or “less than and equal to” and how the symbols are written .
Give the example: You must be 13 years or older to watch some movies. Written as an inequality: ≥ 13