1. T. Trimpe 2008 http://sciencespot.net/
Lesson 1: Length
T. Trimpe

2. English vs. Metric Units
Which is longer?
A. 1 mile or 1 kilometer
B. 1 yard or 1 meter
C. 1 inch or 1 centimeter
1.6 kilometers
1 mile
1 yard = meters
1 inch = 2.54 centimeters
Left Image: Right Image:

3. Click the image to watch a short video about the meter.
Metric Units km m cm mm
The basic unit of length in the metric system in the meter and is represented by a lowercase m.
Standard: The distance traveled by light in absolute vacuum in 1⁄299,792,458 of a second.
Metric Units
1 Kilometer (km) = 1000 meters
1 Meter = 100 Centimeters (cm)
1 Meter = 1000 Millimeters (mm)
Click the image to watch a short video about the meter.
Which is larger?
A. 1 meter or 105 centimeters
B. 4 kilometers or 4400 meters
C. 12 centimeters or 102 millimeters
D millimeters or 1 meter

4. Measuring Length How many millimeters are in 1 centimeter?
1 centimeter = 10 millimeters
1 decimeter (dm) = 10 centimeters
How many millimeters are in 1 centimeter?
What is the length of the line in centimeters? _______cm
What is the length of the line in millimeters? _______mm
What is the length of the line to the nearest centimeter? ________cm
HINT: Round to the nearest centimeter – no decimals.
Ruler:

5. Physical Science Length Challenge 1
L. LaRosa for T. Trimpe

6. Find the length (antennae to feet) of the following insects to the nearest whole or half cm:

7. Find the length (antennae to feet) of the following insects to the nearest whole or half cm:

8. Physical Science Length Challenge 2
L. LaRosa for T. Trimpe

9. Find the lengths of the following pink lines to the nearest mm:

10. Find the lengths of the following pink lines to the nearest mm:

11. Physical Science Length Challenge 3
L. LaRosa for T. Trimpe

12. Complete the following conversions:
3 cm = _____ mm
15 cm = ____ mm
49 cm = ____ mm
103 cm = ____ mm
5 mm = _____ cm
19 mm = ____ cm
74 mm = ____ cm
158 mm = ____ cm

13. X 10 ÷ 10 Complete the following conversions: 5 mm = 0.5 cm
3 cm = 30 mm
15 cm = 150 mm
49 cm = 490 mm
103 cm = 1,030 mm
X 10
÷ 10

14. Physical Science Length Challenge 4
L. LaRosa for T. Trimpe

15. Find the lengths of the following pencils in cm & mm:
Images from

16. Find the lengths of the following pencils in cm & mm:
Images from

17. Physical Science Length Challenge 5
L. LaRosa for T. Trimpe

18. Complete the following conversions for centimeters and meters:
1,955 cm = ___ m
178 cm = ____ m
2,299 cm = ___ m
42 cm = ____ m
1. 8 m = ____ cm
0.56 m = ____ cm
2.3 m = ____ cm
0.02 m = ____ cm

19. Complete the following conversions for centimeters and meters:
1,955 cm = m
178 cm = 1.78 m
2,299 cm = m
42 cm = 0.42 m
1. 8 m = 180 cm
0.56 m = 56 cm
2.3 m = 230 cm
0.02 m = 2 cm
÷ 100
x 100