**BEHAVIOURAL OBJECTIVE(S):** At the ends of the lesson, the students should be able to:

(1) Use the inequality symbols;

(2) Write and interpret linear inequalities in one variable!

(3) Solve linear inequalities in one variable.

**PREVIOUS KNOWLEDGE**: The students have been introduced to linear algebra in their previous lesson.

**REFERENCE(S): ** New general Mathematics for junior secondary schools by MF Macrae, AO Kalejaiye chapter 22 pages 196-204 and MAN Mathematics for junior secondary schools chapter 11 pages 116 – 119.

**TEACHING METHODS**: The teacher makes use of discussion method and questioning method.

**PRESENTATION**: The teacher explains to the students by taking the following steps.

**STEP 1:** The teacher revises the previous lesson with the students.

**STEP 2:** The teacher make use of inequality symbols

**STEP 3:** The teacher write and interpret linear inequalities in one variable

**STEP 4:** The teacher solve linear inequalities in one variable

** CONTENT(S) LINEAR INEQUALITIES**

In solving mathematical problems, we always use the equal sign, =, more often than any other signs or symbols. For example, 5 + 3 = 8 is a simple equality.

However, when quantities are not equal, they are written 5 + 5 ≠ 8.

Where ≠ means is not equal to.

We can also write 5 + 5 > 8

Where > means is greater than.

Similarly, we can write: 3 + 3 < 8.

Where < means is less than.

=, <, > are inequality symbols.

**Note**

= means equal to (you are familiar with)

< means less than

> means greater than

**Class activity 1**: Re-write each of the following using either > or <

- 5 is less than 8
- -1 is greater than -3
- M is greater than 5

**Class activity 2**: State which statement is true and which is false

- -1 < -3
- -2 > -3 -4

Example 1: I have x naira. I spend ~~N~~200. The amount I have left is less than ~~N~~50. Write an inequality in x.

**Solution**

I have x naira means ~~N~~x

I spent N200 out of ~~N~~x means ~~N~~x – N200 = ~~N~~(x – 200)

Less than N50 means ~~N~~(x – 200) < N50

**Example 2**: If 3 is subtracted from twice a number (p), the result is greater than 15.

**Solution**

Twice a number p means 2 multiply by p = 2p

Subtracted by three mean 2p -3

The result is greater than 15 means 2p – 3 > 15

ASSIGNMENT: Write an inequality in terms of the given unknown.

- The cost of the food,
~~N~~x, was over~~N~~500 - The time taken, t min, was under 5 min.

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