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 = 0.94 meters
1 inch = 2.54 centimeters
Left Image: Right Image:

3. Metric Units km m cm mm
The basic unit of length in the metric system is the meter and is represented by a lowercase m.
Standard: During the 18th century scientists measured the distance from the earth’s equator to its North Pole and divided it into ten million parts.
This is how they came up with the length of the standard meter.
Metric Units
1 Kilometer (km) = 1000 meters
1 Meter = 100 Centimeters (cm)
1 Meter = 1000 Millimeters (mm)
(Stop at 1:17)
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
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. Scale To figure out Scale: a) Subtract the two #’s you know for sure
b) Divide by the # of tick marks
How do I round my measurement?
Pretend there are 10 imaginary tick marks between the known ticks.
Record your answer to this estimated tick mark.

6. Practice (a) Length of the line in centimeters ______
(b) Length of the line to the nearest centimeter _______
(c) Height of the rectangle to the nearest millimeter _______
(d) Width of the rectangle to the nearest millimeter _______
(e) Radius of the circle to the nearest millimeter _______
(f) Diameter of the circle in centimeters ________
(g) Diameter of the circle to the nearest centimeter _______

7. Use a meterstick!