Personal References for Metric Length
4.9 Personal References for Metric
Length
 Measure your pencil.
 Record the measurement on your graph!
 Without measuring, try to find something in the
classroom whose length or height is about 15
centimeters.
 Be ready to explain how you made your choice.
4.9 Personal References for Metric
Length
 Let’s read through page 130 in the Student Reference
Book (hard cover).
 How are personal measurement references useful?
 In this lesson, we will be looking for personal
references for 1 centimeter, 10 centimeters (1
decimeter), and 1 meter.
 Estimate then check.
4.9 Personal References for Metric
Length
 Use a ruler, meter stick, or tape measure to find
common objects that have lengths of 1 centimeter, 1
decimeter, and 1 meter. The lengths do not have to be
exact, but they should be close. Ask a friend to look
for references with you. You can find more than one
reference for each unit. Let’s share afterwards.
4.9 Personal References for Metric
Length
Unit of Measure
1 Centimeter (cm)
1 Decimeter (dm),
or 10 Centimeters
1 Meter (m)
Personal References
4.9 Personal References for Metric
Length
 We can use the length of something we know about to
compare for the length of something we don’t.
 For example. How long is your finger across?
 Now use your finger to measure the length of your
math journal.
4.9 Personal References for Metric
Length
 Let’s work though handout page 131 together.
Object
Length of Math Journal
Width of Math Journal
Height of desk
Width of desk
Estimated
Length
Actual Length
4.9 Personal References for Metric
Length
 Let’s review metric conversions.
 It’s a base _____ system.
 Meter to centimeter: multiply by ____
 Centimeter to meter: divide by ____
 Meter to millimeter: multiply by _____
 Millimeter to meter: divide by _____
 Centimeter to Millimeter: multiply by ____
Millimeter to Centimeter: divide by _____
4.9 Personal References for Metric
Length
 18 cm = _____mm
_____cm = 40 mm
 3 m = ______ mm
4 m = ______ cm
 _____ m = 700 cm
4.6 m = _____ cm
 7.94 m = _____ cm
_____ m = 450 cm
 ____ m = 23 cm
0.6 m = ____ cm
4.9 Personal References for Metric
Length
 Measure to the nearest ½ cm
 That does not mean only the ½, but the wholes as well!
 12. About _____ centimeters
 13. About ____ centimeters
4.9 Personal References for Metric
Length
 Practice – Remember, Just like ABC order!!!
 0.68 ______0.32
 9.13 ____9.03
 0.65 _____0.6
4.9 Personal References for Metric
Length
 Homework: Handout page 71