3-9 Practice B

Name Date Class
LESSON
3-9
Each square root is between two integers. Name the integers.
1. �6� 2. �20� 3. �28� 4. �44�
5. �34� 6. �17� 7. �31� 8. �52�
Use a calculator to find each value. Round to the nearest tenth.
9. �14� 10. �42� 11. �21� 12. �47�
13. �58� 14. �60� 15. �35� 16. �75�
17. �66� 18. �55� 19. �67� 20. �80�
Police use the formula r � 2�5L� to approximate the rate of speed
in miles per hours of a vehicle from its skid marks, where L is the
length of the skid marks in feet.
21. About how fast is a car going that leaves skid marks of 80 ft?
22. About how fast is a car going that leaves skid marks of 245 ft?
r
23. If the formula for finding the length of the skid marks is L � ��, 20
what would be the length of the skid marks from a vehicle
traveling 80 mi/h?
Copyright © by Holt, Rinehart and Winston. 84 Holt Middle Holt Pre-Algebra
School Math
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Practice B
Finding Square Roots
2

LESSON
3-9
Each square root is between two integers. Name the integers.
1. �10� 2. �26� 3. �8� 4. �19�
3 � �10 � � 4
5. �5� 6. �33� 7. �15� 8. �39�
Use a calculator to find each value. Round to the nearest tenth.
9. �12� 10. �18� 11. �7� 12. �24�
13. �38� 14. �45� 15. �8� 16. �22�
17. �54� 18. �27� 19. �40� 20. �48�
The distance that a person can see from a certain height
to the horizon can be determined by using the formula
View � �1.6 �eight • h�
where the height is in feet and the
result is in statute miles (defines miles between cities).
21. How far to the horizon could you see if standing on top of Pike’s
Peak in Colorado, elevation 14,110 ft? Round the answer to the
nearest tenth.
150.3 statute miles
22. How far to the horizon could you see if flying in a plane at an
altitude of 30,000 ft? Round the answer to the nearest tenth.
219.1 statute miles
Copyright © by Holt, Rinehart and Winston. 83 Holt Holt Middle Pre-Algebra Copyright © by Holt, Rinehart and Winston. School Math
84 Holt Holt Middle Pre-Algebra
School Math
All rights reserved.
LESSON
3-9
Practice A
Finding Square Roots
2 � �5� � 3
3.5
6.2
7.3
Copyright © by Holt, Rinehart and Winston. 133 Holt Middle Holt Pre-Algebra School Math
All rights reserved.
5 � �26 � � 6
5 � �33 � � 6
4.2
6.7
5.2
2 � �8� � 3
3 � �15 � � 4
2.6
2.8
6.3
4 � �19 � � 5
6 � �39 � � 7
Use a calculator to find each value. Round to the nearest tenth.
Use the indicated letter to graph each point on the number line.
1. A: �1.21 � 2. B: ��2.56 � 3. C: �0.36 � 4. D: ��0.09 �
Use guess and check to estimate each square root to two
decimal places.
5. ��141 � 6. �195 � 7. ��0.024 �5� 8. �47.7 �
Find each product to two decimal places.
9. �64� • �24� 10. ��53� • �38� 11. �35� • (��16�) 12. �25� • �28�
13. �112 � • �38� 14. �77� • �142 � 15. ��66� • (��98�) 16. �81� • (��217 �)
Find each number to two decimal places.
17. What number squared is 48? 18. What number squared is 235?
6.93
15.33
19. What number squared is 604? 20. What number squared is 558?
24.58
23.62
21. If the distance in feet traveled by a falling object is determined
by the formula d � 16t 2 , in which t is the time in seconds, find
the distance a falling object traveled in 22 sec.
7744 ft
22. If the distance traveled by the falling object was 3600 ft, how
many seconds did it take to fall?
15 sec
Copyright © by Holt, Rinehart and Winston. 85 Holt Holt Middle Pre-Algebra School Math
All rights reserved.
Practice C
Finding Square Roots
B D C A
�1.6 �1.4 �1.2 �1 �0.8 �0.6 �0.4 �0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
�11.87
39.19
65.24
13.96
�44.88
104.57
�0.16
�23.66
80.42
4.9
4.7
6.9
6.91
26.46
�132.58
LESSON
3-9
Each square root is between two integers. Name the integers.
1. �6� 2. �20� 3. �28� 4. �44�
5. �34� 6. �17� 7. �31� 8. �52�
5 � �34 � � 6
Use a calculator to find each value. Round to the nearest tenth.
9. �14� 10. �42� 11. �21� 12. �47�
13. �58� 14. �60� 15. �35� 16. �75�
17. �66� 18. �55� 19. �67� 20. �80�
Police use the formula r � 2�5L � to approximate the rate of speed
in miles per hours of a vehicle from its skid marks, where L is the
length of the skid marks in feet.
21. About how fast is a car going that leaves skid marks of 80 ft?
40 mi/h
22. About how fast is a car going that leaves skid marks of 245 ft?
70 mi/h
2
r
23. If the formula for finding the length of the skid marks is L � ��, 20
what would be the length of the skid marks from a vehicle
traveling 80 mi/h?
320 ft
All rights reserved.
LESSON
3-9
Practice B
Finding Square Roots
2 � �6�� 3
3.7
7.6
8.1
4 � �20 � � 5
4 � �17 � � 5
6.5
7.7
7.4
5 � �28 � � 6
5 � �31 � � 6
4.6
5.9
8.2
To locate a square root between two integers, refer to the table.
6 � �44 � � 7
7 � �52 � � 8
Locate �260 � between two integers.
260 is between the perfect squares 256 and 289: 256 � 260 � 289
So: �256 � � �260 � � �289 �
And: 16 � �260 � � 17
Use the table to complete the statements.
1. 36 � 39 � 49
2. 121 � 130 � 144
�36 � � �39� � �49 �
�121 � � �130 � � �144 �
6 � �39� � 7
11 � �130 � � 12
After locating a square root between two integers, you can
determine which of the two integers the square root is closer to.
27 is between the perfect squares 25 and 36: 25 � 27 � 36
So: �25� � �27� � �36�
And: 5 � �27� � 6
The difference between 27 and 25 is 2;
the difference between 36 and 27 is 9.
So, �27�, is closer to 5.
Complete the statements.
4. 100 � 106 � 121 5. 225 � 250 � 256
�100 � � �106 � � �121 �
�225 � � �250 � � �256 �
10 � �106 � � 11
15 � �250 � � 16
106 � 100 � 6
250 � 225 � 25
121 � 106 � 15
256 � 250 � 6
�106 � is closer to 10 than 11 �250 � is closer to 16 than 15
Copyright © by Holt, Rinehart and Winston. 86 Holt Holt Middle Pre-Algebra School Math
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Reteach
Finding Square Roots
Number 1 2 3 4 5 6 7 8 9 10
Square 1 4 9 16 25 36 49 64 81 100
Number 11 12 13 14 15 16 17 18 19 20
Square 121 144 169 196 225 256 289 324 361 400
25 � 27 � 36
2 9
6.9
8.7
8.9