Grade 8 Math Benchmark 3: Growing, Growing, Growing Written Test
Part 1: Multiple Choice (2 points each)
48
4-4
1. Simplify:
A
4-32
B 4-2
C 44
D 412
2. Which expression is equivalent to 47 x 4-5?
A 412
B 42
C 4-2
D 4-35
3. Which number goes in the numerator to make the equation true?
? = 23
2-6
A
2-2
B 2-3
C
2-9
D 2-18
4. A lab has two bacteria cultures. Culture A contains 8 x 104 bacteria, and culture B contains 4 x 106
bacteria. How do the two cultures compare in size?
A Culture A contains twice as many bacteria as culture B
1
B Culture A contains as many bacteria as culture B.
2
1
C Culture A contains
as many bacteria as culture B.
25
1
D Culture A contains
as many bacteria as culture B.
50
5. The speed of light in a vacuum is 299,792,458 meters per second. Which number, written in scientific
notation, is the best approximation of the speed of light?
A 0.3 x 107 meters per second
C 3.0 x 107 meters per second
B 0.3 x 108 meters per second
D 3.0 x 108 meters per second
6. A micron is approximately 4 x 10-5 inch. The diameter of the circular hole made by a pin in a
sheet of paper is 2,000 microns. Which amount is closest to the diameter of the circular hole?
A 2 x 10-2 inch
B 8 x 10-2 inch
C 2 x 10-3 inch
D 8 x 10-3 inch
7. At a given time, Saturn was 9.1 x 108 miles from the Sun and Earth was 9.3 x 107miles from the Sun.
By what distance is one planet closer to the Sun than the other planet?
A 2 x 101
B 2x1015
8. Evaluate
(2.4 x 104)(4.5 x 103)
A 1.08 x 107
B 1.08 x 108
9. Determine the product.
A 1.7x 107
C 8.17 x 107
C 1.08 x 1012
D 8.17 x 108
D 1.08 x 1013
800.5 x (2 x 106)
B 1.601 x 107
C 1.7x109
D 1.601 x 109
10. The combined volume of all the tanks at an aquarium is 1.25 x 106 gallons. The aquarium plans
to install a new dolphin tank with a volume of 250,000 gallons. What will be the total volume of all
of the tanks at the aquarium after the new dolphin tank is installed?
A
1.5x105
B 3.75 x 1 0 5
C 1.5 x 106
D 3.75 x 106
Part 2: Written Response
1. (4 points) Which expression is not equivalent to 6 3
66
A 1
62
B 6-3
C 1
216
Explain why each one of the other possible answers is wrong.
Correct Answer ______
Explanation 1:
Explanation 2:
Explanation 3:
D 1
63
2. (6 points) Ms Harris is a contestant on a quiz show. Every time she answers a question correctly, her winnings
double. If she answers the first question correctly, she wins $1000. If she answers the second question correctly, she
wins $2000. For the third correct answer she wins $4000 and so on.
a) Complete the table to show Ms Harris’s winnings after each correct answer
Correct Answers
Winnings
1
2
3
4
5
6
7
b) On the grid above, graph the data from the table (correct answers, winnings)
c) How many questions must Ms Harris answer correctly to win $256,000?
Answer: _____________
Show your work:
3. (4 points) In answering the following, you should give at least two reasons for each part.
a) Explain how linear and exponential functions are different:



b) Explain how linear and exponential functions are the same:


