grade 7 demo topic

1. Hi!!!

2. Evaluating Algebraic
Expression
TOPIC IN MATHEMATICS7
Prepared by :
SHAHANI CATALAN EDUARDO
Teacher I Applicant

3. Review:
What is an algebraic expression?
An algebraic expression is a mathematical
statement that contains a combination of
numbers, symbols, variables and
mathematical operators. It does not have
an equal sign.
Example:
2x + 3
y2 – 4y + 4
5x + 2y

4. Drill: SAGOT MO,PUNTOS MO
Find the answer to the following multi operation mathematical expression
by connecting the expression in column A to the corresponding answer in
column B.
A B
(3)(8) – (14+10)
(2+6)(2-3)
(2)(3) + 4 - 5
5
-8
0

6. Activity 1
_
_
Suppose numbers are assigned to letters of the alphabet as
follows: Let
A=1 E=5 I=9 M=13 Q=17 U=21 Y=25
B=2 F=6 J=10 N=14 R=18 V=22 Z=26
C=3 G=7 K=11 O=15 S =19 W=23
D=4 H=8 L=12 P=16 T=20 X=24
1. Using this, find the value of your first name by adding the
values of its digits. For example:
S H A H A N I
19 + +
1 = 60
2. Compare it with the values of the names of your
classmates.
+
8
8 + 1 + 14 + 9

7. When a number is substituted or replaced for
the variable in a given algebraic expression,
the expression takes a numerical value.
Finding the value is what we call
Evaluating Algebraic Expression

8. Objectives:
a. Identify the steps in evaluating algebraic expressions
b. Apply the steps in evaluating algebraic expressions
c. Solve word problems involving algebraic expressions

9. Evaluate 6x2 + 3 ; when
1.) x = 0 2.) x = -2
In example 1, evaluate 6x2 + 3 if x = 0
Step 1: Substitute/replace x with 0 in the given algebraic
expression.
6(0)2 + 3
Step 2: Perform the indicated operations by following the
PEMDAS rule.
6(0)2 + 3
6(0) + 3
0 + 3
3

10. Example 2.
Evaluate 6x2 + 3 if x = -2
Step 1: Substitute/replace x with -2 in the given
algebraic expression.
6(-2)2 + 3
Step 2: Perform the indicated operations by following the
PEMDAS rule.
6(-2)2 + 3
6(4) + 3
24 + 3
27

11. 12x – y
3 – 2
1

12. 5. Your output will be scored according to this
standard:
1.Group yourselves by 4 according to your nearest
neighbor (classmate) in your community.
2.Choose your activity to be performed from set A
and Set B
3. Take a video while your classmate/groupmate is
answering on how he/she evaluates algebraic
expression.
4. Submit or send the video (with names of the
members) together with a pictures of your output on
facebook account Shahani Eduardo thru messenger
within a day.
Group Activity

13. Cooperative Learning Rubrics
Excellent
5 points
Acceptable
3 points
Minimal
1 point
Accuracy Correct answer.
Following all
the steps.
Correct answer,
but missing some
of the steps.
Wrong answer.
Missing the
correct steps.
Time Frame First group to
pass within the
time limit.
Following groups to
pass within the
time limit.
Groups that
passes
exceeding the
time limit.
Cooperation All members
doing their
assigned tasks
cooperatively.
Some members did
not cooperate in
the activity.
Few members
do the activity.

14. Find the value of each expression and write the answer
in the square.
Set A Set B
When x = 5 When x = 7
X = 5 X = 7
(x
-
3)
2
2x - 11
3x
2
+
2x
-
3
3x2 + 2x - 3
2x
-
11
(x
-
3)
2
2x – 11
2(5) – 11
10 – 11
-1
-1
2x – 11
2(7) – 11
14 – 11
3
3
7 10
82
3x2 + 2x – 3
3(5)2 + 2(5) – 3
3(25) + 10 – 3
75 +10 – 3 = 82
158
3x2 + 2x – 3
3(7)2 + 2(7) – 3
3(49) + 14 – 3
147 +14 – 3 = 158
4
(x – 3)2
(5 – 3)2
(2)2 = 4
16
(x – 3)2
(7 – 3)2
(4)2 = 16

15. Word Problem
Seth wanted to fence his garden using a cyclone
wire. He needs to find the perimeter of his
garden to determine the length of a cyclone wire
he will be using. Find the perimeter of his
rectangular garden which is 9 meters long and 4
meters wide.
length (l) = 9 meters
width (w) = 4 meters
l
l
w w
l + w + l + w
9 + 4 + 9 + 4
= 26 meters

16. Generalization
What are the steps to follow in
evaluating algebraic expression?
1. Substitute/Replace the variable by
the given number value.
2. Perform the indicated operation by
following the PEMDAS rule.

17. Evaluation
Complete the table by evaluating the
given expression.
X X2 – 7x + 12
0
1
-2
3
-4
12
6
30
0
56

18. Assignment:
1.) Maria will be 37 years old in two years.
Solve the problem. Maria is 5 more
than thrice the age of her son. In
two years, how old will Maria be if
her son is 10 years old now?

19. THANK YOU!!!
Have a nice day!!!