Comparing and Ordering Decimals
Mount Logan in the Yukon Territory is the highest mountain in Canada.
It is 5.959 km high!
Explore j
This table shows the heights
Province/Territory
Mountain
Height (km)
of the highest mountains
Alberta
Columbia
3.747
British Columbia
Fairweather
4.663
Manitoba
Baldy
0.832
Use any materials or strategies
New Brunswick
Carleton
0.817 .
you wish.
Newfoundland
and Labrador
Caubvick
1.652
Order the heights from least
to greatest.
Nunavut
Barbeau Peak
2.616
in some Canadian provinces
and a territory.
S h o w and
Share
Share your results with another pair of students.
Explain the strategies you used to order the heights.
An unnamed peak in the Northwest Territories is 2.773 km high.
Where does this height fit in your ordered list?
Explain why it fits there.
Connect J
Many organisms are too small
Micro-organism
Length (mm)
to be seen with the naked eye.
Tardigrade
0.15
to study t h e m .
Euglena
0.139
Here are the lengths of
Vorticella
0.11
4 micro-organisms.
Paramecium
0.125
Scientists use a microscope
Here are three ways to order the lengths from greatest to least.
>
Use place value. Write each decimal in a place-value chart.
Tenths
Hundredths
Thousandths
1
5
0
0
1
3
9
0
1
1
0
0
1
2
5
Ones
Tardigrade
Euglena
Vorticella
Paramecium
0
<
Compare the ones. All four numbers have 0 ones.
Compare the tenths. All four numbers have 1 tenth.
Compare the hundredths. 5 hundredths is the greatest number
of hundredths, then 3 hundredths, 2 hundredths, and 1 hundredth.
The numbers in order from greatest to least are: 0.15, 0.139, 0.125, 0.11
>
Use equivalent decimals.
Write each decimal in thousandths.
0.15 is 0.150, or 150 thousandths.
0.139
is
139 thousandths.
0.11 is 0.110, or 110 thousandths.
0.125
is
125 thousandths.
Compare the numbers of thousandths.
From greatest to least: 0.150, 0.139, 0.125, 0.110
>
Use a number line.
0.15,0.139,0.11, and 0.125 are between 0.1 and 0.2.
Use equivalent decimals.
So, label the endpoints of the number line 0.10 and 0.20.
Divide the interval between 0.10 and 0.20 to show hundredths.
0.10
1 8 8
0.11
0.12
0.13
0.14
0.15
0.16
0.17
0.18
0.19
0.20
Unit 5 Lesson 7
Divide t h e h u n d r e d t h s t o s h o w t h o u s a n d t h s .
Mark a d o t for each n u m b e r .
0.1 1
0.10
0.11
0.125
0.12
0.13
0.1:3!)
0.15
0.14
0.15
0.16
0.17
0.18
0.19
0.20
The f a r t h e r t o t h e r i g h t o n t h e n u m b e r line, t h e greater a n u m b e r is.
So, reading t h e n u m b e r s f r o m r i g h t t o left gives t h e l e n g t h s
f r o m greatest t o least.
The lengths f r o m greatest t o least are: 0.15 m m , 0.139 m m , 0.125 m m , 0.11 m m
Practism
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1. Use place value.
Order t h e decimals in each set f r o m least t o greatest,
a) 0.8,0.3,0.7
b) 0.5,0.2,0.1
<c) 0.4,0.7,0.6
d) 0.12, 0.99, 0.81
e) 0.73, 0.19, 0.42
fi )
g) 0.529,0.592,0.925
h) 0.125,0.118,0.181
i) 0.354, 0.500,0.345
0.88, 0.98, 0.89
2. Copy and c o m p l e t e . Use > , < , or = .
a) 0.2 •
0.4
b) 0.06 •
d) 0.9 •
0.90
e) 0.745 •
0.01
0.75
c) 0.694 •
0.690
f ) 0.624 •
0.8
3. Use e q u i v a l e n t decimals.
Order t h e decimals in each set f r o m least t o greatest.
a) 0.576,0.02,0.009, 0.1,0.002
b) 0.06, 0.278,0.003,0.15,0.7
4. Order t h e n u m b e r s f r o m least t o greatest.
a) 24.3, 24.7, 24.1
b) 0.59, 0.95, 0.57
c) 1.76, 1.63,
1.78
5. Order t h e n u m b e r s f r o m greatest t o least.
a) 0.571, 3.53, 0.538
b) 1.002, 1.35, 1.267
c) 1 5.2, 15.012, 16
6. Write a n u m b e r b e t w e e n 6.73 a n d 6.741.
How did you choose the number?
7. Lian's paper airplane f l e w 4.247 m a n d Maude's f l e w 4.25 m.
"v
W h o s e plane f l e w farther? Show h o w y o u k n o w .
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8. Write t w o n u m b e r s b e t w e e n 1.51 a n d 1.52.
H o w d i d y o u choose t h e n u m b e r s ?
Unit 5 Lesson 7
1 8 9
This table shows the results of a watermelon
Name
Distance (m)
a) Whose seed went the greatest distance?
Vladimir
2.357
b) Whose seed went the least distance?
Abu
2.4
c) Whose seed went farther than Poppy's
Poppy
2.35
Suki
1.943
Cy
1.7
Luis
2.438
seed-spitting contest.
but not as far as Luis'?
d) Order the distances from greatest to least.
10. Use the graph.
Masses of Some Hummingbird Eggs
0.7 - j
The masses in grams of the hummingbird
0.6
eggs, in no specific order, are:
•
•
-
5
°- ~ I I
3
0.482, 0.44, 0.32, 0.56, 0.374
- 0 . 4 -
What is the mass of the egg of:
2
n
n
n
{ § 0 . 3 0
0.1
a) the Costa's hummingbird?
HI
-
2
1
o - —'—'—L—I—LJ—I—I—I—I—I
b) the bee hummingbird?
c) the black-chinned hummingbird?
Hummingbirds
11- Which number is closest to 6?
/
Explain how you know.
5.014, 6.4, 6.002, or 5.91
12. Copy each statement.
Write a decimal with thousandths to make each statement true,
a) 0.43 > •
b) 5.7 < •
c) 32.002 >
d) 2 . 3 1 < D
e) 21.24 > •
f) 0.1 >
•
•
13. Grady is 1.35 m tall. His sister is 1.7 m tall.
Grady's mother is 1.59 m tall.
a) Who is the tallest?
b) Who is the shortest?
c) Do you think Grady is older or younger than his sister? Explain.
14. Order these numbers on a number line: 1.27, 1.284, 1.236, 1.2, 1.279
A student says that 7.52 is to the left of 7.516
on a number line because 52 is less than 516.
Is the student correct? Explain your answer.
1 9 0
ASSESSMENT F O C U S
I
Question 11
Unit 5 Lesson 7