Transcript Lesson

th
8
grade lesson plan (day 1 )
Students will be learning how to use generate equivalent expressions for numbers with both positive and
negative exponents. Students should be seated randomly in groups of 4 and will need one whiteboard and
marker per group.
1) After explaining the learning goal, show students the following video:
https://www.brainpop.com/math/numbersandoperations/exponents/
Brainpop username is :Safford
Password is: brainpop
2) After watching the video, show the first slide and relate the distributive property explanations to the
explanations from the video.
3) Review with students the following slides (starting at slide 3). Have students take notes and complete
several of the problems from slide 7 as a whole group. Depending on the comfort level, you can also have
students work as a team of 4, and then put their final answers on the white boards and discuss solutions
and strategies as a whole group.
4) Ticket out the door: Have students write down one exponent rule on a piece of paper that they
remember from today’s lesson.
Standard:
CCSS.Math.Content.8.EE.A.1
Know and apply the properties of integer exponents to generate
equivalent numerical expressions. For example, 32 × 3-5 = 3-3 = 1/33 =
1/27.
Exponents
5
exponent
3
Power
base
Example: 125  53 means that 53 is the exponential
form of the number 125.
53 means 3 factors of 5 or 5 x 5 x 5
The Laws of Exponents:
#1: Exponential form: The exponent of a power indicates
how many times the base multiplies itself.
x  x  x  x  x  x  x  x
n
n times
n factors of x
Example: 5  5  5  5
3
#2: Multiplying Powers:
If you are multiplying Powers
with the same base, KEEP the BASE & ADD the EXPONENTS!
x x  x
m
So, I get it!
When you
multiply
Powers, you
add the
exponents!
n
mn
2 6  23  2 6  3  29
 512
#3: Dividing Powers: When dividing Powers with the
same base, KEEP the BASE & SUBTRACT the EXPONENTS!
m
x
m
n
mn

x

x

x
n
x
So, I get it!
When you
divide
Powers, you
subtract the
exponents!
6
2
6 2
4

2

2
2
2
 16
Try these:
12
1. 3  3 
2
2
7.
2. 52  54 
3.
8.
a a 
5
2
4. 2s  4s 
2
7
12 8
9.
5. (3)  (3) 
2
6.
3
s t s t 
2 4
7 3
s

4
s
9
3

5
3
s t

4 4
st
5 8
10.
36a b

4 5
4a b
SOLUTIONS
2
2 2
4
a a  a
5 2
a
1. 3  3  3  3  81
2 4
6
2
4
2. 5  5  5  5
2
3.
5
2
4. 2s  4s  2  4  s
2
7
5. (3)  (3)  (3)
2
6.
3
s t s t 
2 4
7 3
s
7
27
23
 8s
 (3)  243
27 43
t
9
5
s t
9 7
SOLUTIONS
12
7.
8.
9.
10.
s
12 4
8
s

s

4
s
9
3
9 5
4
3

3
 81

5
3
12 8
s t
12 4 8 4
8 4
s t s t

4 4
st
5 8
36a b
5 4 85
3
36

4

a
b

9
ab

4 5
4a b
#7: Negative Law of Exponents: If the base is powered
by the negative exponent, then the base becomes reciprocal with the
positive exponent.
So, when I have a
Negative Exponent, I
switch the base to its
reciprocal with a
Positive Exponent.
Ha Ha!
If the base with the
negative exponent is in
the denominator, it
moves to the
numerator to lose its
negative sign!
x
m
1
 m
x
1
1
5  3 
5
125
and
3
1
2

3
9
2
3
th
8
grade lesson plan (day 2 )
Students will be learning how to use generate equivalent expressions for numbers with both positive and
negative exponents. Students should be seated randomly in groups of 4 and will need one whiteboard and
marker per group.
1) After explaining the learning goal, review with students how to evaluate a number with a negative
exponent
Examples
4-2 = 1/42 = 1/16
5 -3 = 1/ 53 = 1/125
2) Students will now participate in the “Negative Exponents Go Fish” activity. Directions are within the
materials. Each group of four should have a set of cards. Play game for 10 minutes
3) Next, have students work in pairs on the School City Practice questions. This practice set should be
turned into their math teacher when completed.
4) Closure – ask students to explain their thinking and solutions about the word problems on the
whiteboard in front of the class. Have students check their work.