CCSS
G3.MD.8
Solve
real world and
mathematical
perimeters
MG 1.1
Choose the
appropriate
tools
and unitsproblems
(metric involving
and U.S.)
and
of polygons, including finding the perimeter given the side lengths, finding an unknown
estimate and measure the length, liquid volume, and weight/mass
side length, and exhibiting rectangles with the same perimeter and different areas or with
of given
objects.
the same area
and different
perimeters.
UNDERLYING SKILLS AND CONCEPTS:
measure length (metric units)
Measure Length in Metric Units
a
K
ey Ide
The metric system uses these
units to measure length.
1,000 meters (m) 1 kilometer (km)
100 centimeter (cm) 1 meter
10 millimeters (mm) = 1 centimeter
E x am p l E
Benchmarks for You
1 meter is about 3 feet long.
Your 12-inch ruler is about
30 centimeters long.
of
1 centimeter is about 1
3
an inch long.
1
2
5
E x am p l E
E x am p l E
3
3
cm
1
Your ruler is only about 30 centimeters long.
So this book is less than a meter long.
2
Think: one meter is 100 centimeters.
Picture 100 centimeters.
4
Is this book more or less than a meter long?
How
tall
am I?
Is the door to the classroom more or less than a meter tall?
Remember, a meter is about the height of a bicycle.
The door to the classroom is taller than a bicycle.
So, the door to the classroom is taller than 1 meter.
page 302
Chapter 26 – Lesson 1
C – © CSL Associates, Inc. All rights reserved.
6
The yarn is about 11 centimeters long.
7
Use a centimeter ruler.
Measure the yarn to the nearest centimeter.
Name
P RAC T I C E
Measure each path to the nearest centimeter.
1. Tim’s house to the traffic light
about 9 cm
about 12 cm
3. Traffic light to library
C – © CSL Associates, Inc. All rights reserved.
2. Tim’s house to the store
4. Library to the bank
about 9 cm
about 8 cm
Does each item measure more than one meter, less than one meter, or
about one meter?
5. a car
6. a ladybug
7. a parrot
more
less
8. a school bus
9. a new crayon
more
Math
Reasoning
less
less
10. width of a door
about 1 meter
Measurement
MR 2.2
11. If an object measures 478 centimeters, what does it measure to the
nearest meter? Tell how you know.
5 meters; Possible answer: I rounded 478 to 500.
I know 100 cm 1 m, so 500 cm 5 m.
Chapter 26 – Lesson 1
page 303
MCX94.HW.CL.G3.FM&Lesson.v211
8/3/04
13:57
Page 202
Name
…at home!
P RAC T I C E
Measure each path to the nearest centimeter.
1. Tim’s house to the library
2. Tim’s house to the park
about 18 cm
about 36 cm
4. Library to the park
about 12 cm
about 18 cm
Does each item measure more than one meter, less than one meter, or
about one meter?
5. a van
6. a beetle
7. a guinea pig
more
less
8. a delivery truck
more
Math
Reasoning
9. a new marker
less
less
10. width of a window
about 1 meter
Measurement
MR 2.2
11. If an object measures 389 centimeters, what does it measure to the
nearest meter? Tell how you know.
4 meters; Possible answer: I rounded 389 to 400.
I know 100 cm 1 m, so 400 cm 4 m.
page 202
Home Resource and Homework
Chapter 26 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
3. Store to school
MCX94TEG3Ch01_32.v8.9.3 2/21/01 14:51 Page 557
Name
P RAC T I C E
Measure each path to the nearest centimeter.
1. Tim’s house to the traffic light
about 9 cm
about 12 cm
3. Traffic light to library
C – © CSL Associates, Inc. All rights reserved.
2. Tim’s house to the store
4. Library to the bank
about 9 cm
about 8 cm
Does each item measure more than one meter, less than one meter, or
about one meter?
5. a car
6. a ladybug
7. a parrot
more
less
8. a school bus
9. a new crayon
more
Math
Reasoning
less
less
10. width of a door
about 1 meter
Measurement
MR 2.2
11. If an object measures 478 centimeters, what does it measure to the
nearest meter? Tell how you know.
5 meters; possible answer: I rounded 478 to 500.
I know 100 cm 1 m, so 500 cm 5 m.
Chapter 26 – Lesson 1
Student Book Page
page 303
Name
…at home!
P RAC T I C E
Measure each path to the nearest centimeter.
1. Tim’s house to the library
2. Tim’s house to the park
about 18 cm
about 36 cm
4. Library to the park
about 12 cm
about 18 cm
Does each item measure more than one meter, less than one meter, or
about one meter?
5. a van
6. a beetle
7. a guinea pig
more
less
8. a delivery truck
more
Math
Reasoning
9. a new marker
less
less
10. width of a window
about 1 meter
Measurement
MR 2.2
11. If an object measures 389 centimeters, what does it measure to the
nearest meter? Tell how you know.
4 meters; Possible answer: I rounded 389 to 400.
I know 100 cm 1 m, so 400 cm 4 m.
page 202
Home Resource and Homework
Chapter 26 Lesson 1
C – © CSL Associates, Inc. All rights reserved.
3. Store to school