Math Grade 8
Expressions and Equations (EE)
Teacher Key
Work with Radicals and Integer Exponents Part 2
Benchmarks that are Measured in this Quizlet
Benchmark Code
Benchmark
Item #
8.SMC.EE.1.3-1.b
Estimate large or small quantities using numbers expressed in the form of a
single digit times a whole-number power of 10
1, 2
8.SMC.EE.1.3-2.b
Compare large quantities to small quantities expressed in the form of a single
digit times a whole-number power of 10
3, 4
8.SMC.EE.1.4-1.c
Perform operations with numbers expressed in scientific notation
8.SMC.EE.1.4-2.c
Choose units of appropriate size for measurements of large or small quantities
using scientific notation
7, 8
8.SMC.EE.1.4-3.c
Interpret numbers that have been expressed in scientific notation which have
been generated by technology
9, 10
8.SMP.1.c
Make sense of problems and persevere in solving them
5, 6, 11
11
August 2015
MATH GR8 EE QUIZLET 2
Teacher Key
NOTES TO TEACHERS
This series of Quizlets is meant to be used for classroom formative assessment. Different from tools to evaluate student learning
summatively, they are meant to be used by teachers as a part of the instructional process.
Some features of these Quizlets are:
 The Quizlets are fully aligned with the Benchmarks.
 Each Quizlet is has a variety of item types: multiple choice (MC), multiple response (MR), short response (SR) and
performance-based (PB).
 The Quizlets were created using Microsoft® Word so that they can be modified.
 Item stems and graphic organizers can be used to create additional assessments that are aligned to the benchmarks.
Quizlets can be used to identify benchmarks where students are struggling or identify individual students who need additional learning
opportunities.
Item
Teacher Key: Work with Radicals and Integer Exponents Part 2
Benchmark Code
Benchmark
Correct
Answer
Number
of Points
1.
8.SMC.EE.1.3-1.b
Estimate large or small quantities using numbers expressed in the form
of a single digit times a whole-number power of 10
D
1
2.
8.SMC.EE.1.3-1.b
Estimate large or small quantities using numbers expressed in the form
of a single digit times a whole-number power of 10
SR
2
3.
8.SMC.EE.1.3-2.b
Compare large quantities to small quantities expressed in the form of a
single digit times a whole-number power of 10
C
1
4.
8.SMC.EE.1.3-2.b
Compare large quantities to small quantities expressed in the form of a
single digit times a whole-number power of 10
SR
2
5.
8.SMC.EE.1.4-1.c
Perform operations with numbers expressed in scientific notation
B
1
6.
8.SMC.EE.1.4-1.c
Perform operations with numbers expressed in scientific notation
SR
2
7.
8.SMC.EE.1.4-2.c
Choose units of appropriate size for measurements of large or small
quantities using scientific notation
A
1
8.
8.SMC.EE.1.4-2.c
Choose units of appropriate size for measurements of large or small
quantities using scientific notation
SR
2
Page 2
MATH GR8 EE QUIZLET 2
Teacher Key
Item
Teacher Key: Work with Radicals and Integer Exponents Part 2 Continued
Benchmark Code
Benchmark
Correct
Answer
Number
of Points
9.
8.SMC.EE.1.4-3.c
Interpret numbers that have been expressed in scientific notation which
have been generated by technology
SR
2
10.
8.SMC.EE.1.4-3.c
Interpret numbers that have been expressed in scientific notation which
have been generated by technology
SR
2
8.SMC.EE.1.4-1.c
Perform operations with numbers expressed in scientific notation
PB
8
11.
8.SMP.1.c
Make sense of problems and persevere in solving them
Page 3
MATH GR8 EE QUIZLET 2
Teacher Key
Explained Answers
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 2. Electron Mass (2 points)
Benchmark: 8.SMC.EE.1.3-1.b Estimate large or small quantities using numbers expressed in the form of a single digit times a whole-number power of 10
Item Stem
Responses
The mass of an electron is 0.000548597 a.m.u. Express this
number as a single digit times a whole number power of 10.
5 × 10–4
Points
2 points for correct
response
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 4. Compare Numbers (2 points)
Benchmark: 8.SMC.EE.1.3-2.b Compare large quantities to small quantities expressed in the form of a single digit times a whole-number power of 10
Item Stem
Responses
Points
−3
6 10
×
4 10−5
Given the numbers 6 × 10–3 and 4 × 10–5, how many times is
the first number compared to the second number?
1.5 ×102
150
2 points for correct
response
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 6. Operations in Scientific Notation (2 points)
Benchmark: 8.SMC.EE.1.4-1.c Perform operations with numbers expressed in scientific notation
Item Stem
Responses
4
10−3
× −6
1.6 10
What is (4 × 10–3) ÷ (1.6 × 10–6) ?
2.5 ×103
or
2500
Page 4
Points
2 points for correct
response
MATH GR8 EE QUIZLET 2
Teacher Key
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 8. Ant Speed (2 points)
Benchmark: 8.SMC.EE.1.4-2.c Choose units of appropriate size for measurements of large or small quantities using scientific notation
Item Stem
Responses
2 cm
1 km
3600 sec
×
×
sec 100000 cm
1 hr
Monica notices that an ant can move at a rate of
2 centimeters every second. How many kilometers per hour
written in scientific notation, can the same ant move?
0.072 km/hr
Points
2 points for correct
response
7.2 × 10–2 km hr
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 9. Galaxy Distance (2 points)
Benchmark: 8.SMC.EE.1.4-3.c Interpret numbers that have been expressed in scientific notation which have been generated by technology
Item Stem
Responses
1017
The Canis Major Dwarf Galaxy is calculated to be 2.36 ×
km from the sun. The Large Magellanic Cloud is calculated to
be 1.69 × 1018 km from the sun. Which distance is less?
2.36 × 1017 km is less
Points
2 points for correct
response
SHORT RESPONSE EXPLAINED ANSWERS
ITEM 10. Electron Proton Mass (2 points)
Benchmark: 8.SMC.EE.1.4-3.c Interpret numbers that have been expressed in scientific notation which have been generated by technology
Item Stem
Responses
The mass of an electron is calculated to be 9.1 × 10 –31 kg.
The mass of a proton is calculated to be 1.7 × 10–27 kg. Which
mass is greater?
1.7 × 10–27 kg is greater
Page 5
Points
2 points for correct
response
MATH GR8 EE QUIZLET 2
Teacher Key
PERFORMANCE-BASED RUBRIC
ITEM 11. Atom Weight (8 points)
Benchmark: 8.SMC.EE.1.4-1.c Perform operations with numbers expressed in scientific notation
Benchmark: 8.SMP.1.c Make sense of problems and persevere in solving them
Item Stem:
Level
Your chemistry teacher wants you to understand how weight is related to atoms.
She gives you the following atomic weights from the periodic chart.
6.02 x
1023
Hydrogen (H) atoms weigh 1 gram
6.02 x
1023
Oxygen (O)
atoms weigh 16 grams
6.02 x
1023
Carbon (C)
atoms weigh 12 gram
6.02 x
1023
Nitrogen (N)
atoms weigh 14 gram
4.0
(7-8
Points)
6.02 x 1023 Sodium (Na) atoms weigh 23 grams
3.0
6.02 x 1023 Chlorine (Cl) atoms weigh 35.5 grams
Part A A molecule of water, H2O, contains 3 atoms (Note: O = O1)
6.02 x 1023 molecules of water, H2O, contains how many total atoms? What would it
weigh?
(5-6
Points)
Part B You may know the formula of other molecules, if not make up any formula
with the atoms above. Calculate the weight of your molecule and the number of
atoms it contains.
Part C Try 6.02 x 1023 molecules of Glucose sugar C6H12O6
Possible Responses:
Part A 6.02 x 1023 molecules water, H2O, contains how many total atoms? What
would it weigh?
Atoms = 3 x 6.02 x 1023 = 18.06 x 1023 = 1.806 x 1024
2.0
(3-4
Points)
It weighs 18 grams
Criteria
In addition to the understanding in Level 3.0, the student
exhibits in-depth inferences and applications that go
beyond what was taught.
The student exhibits no major errors or omissions at
eighth grade level by:

8.SMC.EE.1.4-1.c Performs operations with numbers
expressed in scientific notation by multiplying them
correctly and providing an answer with correct notation.

8.SMP.1.c Make sense of problems and persevere in
solving them by correctly finding the weights of the
molecules.
The student exhibits major errors or omissions regarding
the more complex ideas and processes, but makes no
major errors or omissions regarding the simpler details
and processes at eighth grade level, including:

8.SMC.EE.1.4-1.c Performs operations with numbers
expressed in scientific notation by multiplying but not
using correct notation.

8.SMP.1.c Make sense of problems and persevere in
solving them by approximating the weight of the
molecules.
Part B (answers may vary)
NaCl Atoms = 2 x 6.02 x 1023 = 12.04 x 1023 = 1.204 x 1024
1.0
It weighs 58.5 grams
(1-2
Points)
Part C 24 X 6.02 X 1023 = 144.4 X 1023 = 1.44 X 1025
It weighs 180 grams
0.0
(0
Points)
Page 6
With help, the student demonstrates partial
understanding of some of the score 2.0 elements and
some of the score 3.0 elements at the eighth grade level.
Even with help, the student demonstrates little
understanding of skills.