Download Grade-9-ALGEBRAIC-EXPRESSIONS-Lesson

MATHEMATICS LESSON PLAN
GRADE 9
TERM 1: January – March
PROVINCE:
DISTRICT:
SCHOOL:
TEACHER’S NAME:
DATE:
DURATION:
1 Hour
1. TOPIC: ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
2. CONCEPTS & SKILLS TO BE ACHIEVED:
By the end of the lesson learners should know and be able to:
 recognize and identify conventions for writing algebraic expressions,
 identify and classify like and unlike terms in algebraic expressions,
 recognize and identify coefficients and exponents in algebraic expressions,
 recognize and differentiate between monomials, binomials and trinomials
Grade 9 Lesson Plan: 1+4 Intervention – Term 1
ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
(Draft)
3. RESOURCES:
DBE Book 1, Sasol-Inzalo Book1, textbook
 flow diagrams
 number patterns
 algebraic terminology
5. REVIEW AND CORRECTION OF HOMEWORK (suggested time: 10 minutes)
Homework provides an opportunity for teachers to track learners’ progress in the mastery of
mathematics concepts and to identify the problematic areas which require immediate attention.
Therefore it is recommended that you place more focus on addressing errors from learner
responses that may later become misconceptions.
4. PRIOR KNOWLEDGE:
6. INTRODUCTION (Suggested time: 10 Minutes)
Discuss the following with learners and ask learners to provide suitable examples:
 the difference between an expression and an equation
 the concepts: constant, variable and coefficient
 definition of the term equivalent (expressions)
 conventions used in algebra
Note:

an algebraic expression is made up of numbers, variables and operations signs, that can also
be described in words in some cases they can be described with flow diagrams.

equivalent expressions are algebraic expressions that have different sequences of operations,
but have the same numerical value for any given value of 𝑥.

a convention is something that people have agreed to do in the same way. We write 3 × 𝑥
rather than 𝑥 × 3, and we write 3𝑥 rather than 𝑥3. In algebraic expressions, when multiplying
with variables the multiplication sign is often not shown: We normally write 4𝑥 instead of 4 × 𝑥
and 4(𝑥 − 5) instead of 4 × (𝑥 − 5).
Grade 9 Lesson Plan: 1+4 Intervention – Term 1
ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
(Draft)
Page 2 of 5
7. LESSON PRESENTATION/DEVELOPMENT (Suggested time: 20 minutes)
Learning activities
(Learners are expected
to:)
Teaching activities
Activity 1
Complete the following table with the learners and discuss their
answers.
Words
Flow diagram
Multiply a number by 5
×5
and then subtract 3
from the answer
−3
Learners work in pairs to
do the activities under
classwork
Expression
5𝑝 − 3
2(4𝑥 − 3)
Let learners complete the table on page 117 in the Sasol-Inzalo Book
1.
Activity 2
Consider the expression 8𝑥 2 𝑦 + 5𝑥 3 𝑦 2 − 2 and discuss the following
questions with the learners:
a) Why is 8𝑥 2 𝑦 + 5𝑥 3 𝑦 2 − 2 considered as an expression and not an
equation?
b) How many terms are in the expression?
c) What is the number 8 called?
d) Write down the coefficient of 𝑥 3
e) What name is given to the number −2?
f) What is the value 3 in this expression?
g) What is the term with the highest power of 𝑦?
h) Write the expression in descending order of 𝑦.
i) Determine the value of the expression if 𝑥 = 2 and 𝑦 = −1
Activity 3
With assistance of the learners rewrite the following applying algebraic
conventions:
𝑥×4+𝑥×𝑦−𝑦×3
Let the learners do no 1 (b) on page 120 in the Sasol-Inzalo Book1.
Note:
Highlight the following misconceptions:

𝑥 + 𝑥 = 2𝑥 and NOT𝑥 2 (note the convention is to write 2𝑥 rather than
𝑥2)

𝑥 2 + 𝑥 2 = 2𝑥 2 and NOT 2𝑥 4
Grade 9 Lesson Plan: 1+4 Intervention – Term 1
ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
(Draft)
Page 3 of 5
Learners complete the row
under example 4
Activity 4
Discuss the concepts monomial, binomial, trinomial and polynomial
with learners providing relevant example.
Consider the following table and complete with learners the first row.
Let leaners complete the rest of the table.
Expression
2𝑥 2 + 3𝑥
− 10
𝑘
− 15
3
Type of
Symbol
expression used to
represent
the
variable
Trinomial
𝑥
Constant
−10
Coefficient
of
the second
term is 6
the first
term is
8. CLASSWORK (Suggested time: 15 minutes)
1. Sasol-Inzalo Book 1 pg. 117, no. 1
2. Rewrite the following applying algebraic conventions:
a) 7 × (10 − 𝑥) + (5 × 𝑥 + 3)10
b) −2 × 𝑎 + 𝑏
c) 𝑎2
3. Complete the table.
Expression
6𝑠 3 + 𝑠 2 + 5
4𝑝11
𝑦2 + 1
2
Type of
expression
Symbol used
to represent
the variable
Constant
Coefficient of
𝑠 2 𝑖𝑠 ...
𝑝11 𝑖𝑠 …
2
𝑦 is ...
Grade 9 Lesson Plan: 1+4 Intervention – Term 1
ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
(Draft)
Page 4 of 5
9. CONSOLIDATION/CONCLUSION & HOMEWORK (Suggested time: 5 minutes)
a) Emphasise that:
 an algebraic expression is made up of numbers, variables and operations signs, that can also
be described in words in some cases they can be described with flow diagrams.
 equivalent expressions are algebraic expressions that have different sequences of operations,
but have the same numerical value for any given value of 𝑥.
 a convention is something that people have agreed to do in the same way. We write 3 × 𝑥
rather than 𝑥 × 3, and we write 3𝑥 rather than 𝑥3. In algebraic expressions, when multiplying
with variables the multiplication sign is often not shown: We normally write 4𝑥 instead of 4 × 𝑥
and 4(𝑥 − 5) instead of 4 × (𝑥 − 5).
b) The primary purpose of Homework is to give each learner an opportunity to demonstrate
mastery of mathematics skills taught in class. Therefore Homework should be purposeful and
the principle of ‘Less is more’ is recommended, i.e. give learners few high quality activities that
address variety of skills than many activities that do not enhance learners’ conceptual
understanding.
Carefully select appropriate activities from the Sasol-Inzalo Books, DBE workbooks and/or
textbooks for learners’ homework. The selected activities should address different cognitive
levels.
Recommended Homework:
Sasol-Inzalo Book 1 pg. 118, no. 1, 2.
Grade 9 Lesson Plan: 1+4 Intervention – Term 1
ALGEBRAIC EXPRESSIONS: ALGEBRAIC LANGUAGE (Lesson 1)
(Draft)
Page 5 of 5