05-NEM-Gr4-Chap05
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7:53 AM
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CHAPTER 5
2
You will need
Measuring with
Millimetres
• printer paper
• construction
paper
• a ruler
Goal Use millimetres to measure with precision.
Chantal wanted to know whether printer paper or
construction paper is thicker.
Chantal’s Measurement
I made a stack of 50 sheets of white printer paper.
I made another stack of 50 sheets
of construction paper.
I measured to find out how much
thicker the stack of construction paper is.
The white paper is about 1 cm thick.
The construction paper is between
1 cm and 2 cm thick.
? How can Chantal make a more precise
measurement to compare the stacks?
A. Use a ruler marked with millimetres to answer
these questions.
a) How many millimetres fit between 50 mm
and 70 mm?
b) How many centimetres fit between 50 mm
and 70 mm?
c) The length of an object is about halfway
between 2 cm and 3 cm.
How long could the object be in millimetres?
d) How many millimetres are in 1 dm?
Explain how you know.
126
millimetre
A unit of length
that is shorter than
a centimetre
10 mm = 1 cm
10 mm
or 1 cm
1 mm
0 cm
10
20
30
The space between
the small markings
is 1 mm.
The space from
20 mm to 30 mm is
10 mm, or 1 cm.
NEL
40
05-NEM-Gr4-Chap05
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7:53 AM
Page 127
B. Make 2 stacks of paper like Chantal’s.
C. Measure and record the thickness of each stack of
paper in millimetres.
D. How much thicker is the stack of construction paper?
Reflecting
1. How many millimetres are in 1 m?
Explain how you know.
2. Why are long distances not measured in
millimetres?
3. Why is it possible to be more precise when
measuring in millimetres rather than centimetres?
Checking
4. Compare 25 sheets of construction paper with
25 sheets of white paper.
How much thicker is the stack of construction paper?
Practising
5. Estimate in millimetres.
Measure the object to check your estimate.
a) the thickness of a CD case
b) the length of a paper clip
c) the width of your thumb
d) the thickness of your shirt
6. Look at this line.
a) Estimate how many millimetres you would
have to add to make the line 1 dm long.
b) Measure to check your estimate.
How close were you?
NEL
127