Transcript rttFW 1.4 Scaling Up Prisms.pptx

TEACHER NOTES
1. IT IS CRUCIAL THAT THE CONCEPT AND
SPECIFIC INFORMATION ABOUT SCALE
FACTOR IS THOROUGHLY TAUGHT IN THIS
LESSON AS BECAUSE ONE OF THE THREE
SECTIONS ON TOMORROW’S QUIZ
FOCUSES ON THIS CONCEPT!
Quick Start Expectations
1. Quiz Tomorrow!
2. Fill in planner and HWRS
HW: F&W p. 18-23 #10 a-b, 26-28
3. Get a signature on HWRS
4. On desk: journal, HWRS, pencil, pen
5. Warm Up: next slide… back of HWRS
Warm Up:
Solve for Surface Area
The following polyhedron is a cube.
Front = 12 x 12 = 144
SA= 144 x 6 = 864 square feet
Why can I solve it this way??
12 feet
What are the two key words that explain
what you will explore today?
SCALE FACTOR
Calculate the Surface Area and the Volume of a 1 x 1 x 1
rectangular prism.
SA = 6 sq. in.
Vol = 1 cubic in.
What happens when you double the length(only)?
• What is the SA?
SA = 10 sq. in.
• What is the Volume?
Vol = 2 cubic in.
(1 dimension)
What happens when you double the length AND the width?
• What is the SA?
(2 dimensions)
SA = 16 sq. in.
• What is the Volume?
Vol = 4 cubic in.
What happens when you double the length, the width,
AND the height? (3 dimensions)
• What is the SA?
SA = 24 sq. in.
• What is the Volume?
Vol = 8 cubic in.
What happens to the SA…
• when you apply a scale factor of 2?
 All 3 dimensions are multiplied by 2.
 What is the relationship between the original SA and
the new SA?
 What is the relationship between the scale factor and
how many times larger the SA is?
What happens to the Volume…
• when you apply a scale factor of 2?
 All 3 dimensions are multiplied by 2.
 What is the relationship between the original
Vol. and the new Vol.?
 What is the relationship between the scale factor
and how many times larger the Vol. is?
Together as a class…
Double any ONE of the dimensions – length, width or height
Triple any ONE of the dimensions – length, width or height
Halving any ONE of the dimensions – length, width or height
V = 4 x 8 x 12 = 384 cubic in.
V=
(V x 2 x 2 x 2)
V=
(V x 1.5 x 1.5 x 1.5)
V=
(V x 0.5 x 0.5 x 0.5)
You can find these answers by multiplying the
3
original box volume by the
f
Work in Groups…
25 x 200 = 5,000 cm or 50 meters long
30 m = 3,000 cm
3,000
200
= 15 cm
2
2
2
20 cm x 200 = 800,000 cm or 80 m
3
100 cm
x 200
3
3
2
3
= 800,000,000 cm or 800 m
Exit Ticket?
HW: F&W p. 18-23 #10 a-b, 26-28