Title
Grade
Learning Goal
SBAC
Assessment
Claim
Animals of Rhomar
7
Students will use ratios, rates, proportions, charts and graphs to
represent proportional relationships.
2: Problem Solving-Students can solve a range of complex well-posed
problems in pure and applied mathematics, making productive use of
knowledge and problem solving strategies.
3: Communicating Reasoning-Students can clearly and precisely
construct viable arguments to support their own reasoning and to
critique the reasoning of others.
Item Type
Standards
Practice(s)
Task Overview
4: Modeling and Data Analysis-Students can analyze complex, realworld scenarios and can construct and use mathematical models to
interpret and solve problems.
Constructed Response, Performance Task
7.RP 2 Recognize and represent proportional relationships between
quantities.
a. Decide whether two quantities are in a proportional
relationship, e.g., by testing for equivalence ratios in a table or
graphing on a coordinate plane and observing whether the graph is
straight line.
b. Identify the constant of proportionality (unit rate) in tables,
graphs, diagrams and verbal descriptions of proportional
relationships.
c. Explain what a point (x,y) on the graph of a proportional
relationship means in terms of the situation.
2, 3, 4, 5, 7, 8
Students will be asked to solve some constructed response questions
involving ratios, unit rates and proportions. In part two, students will
put their information into charts and will graph it. Students will need
to interpret that the graph shows a proportional relationship. The
performance task requires students to compare and contrast their
animal with another groups animals using the tools from part one and
two to determine whether a proportional relationship exists.
Animals of Rhomaar
There are scientists studying the different animals on the planet Rhomaar. The scientists
have collected data for the first ten years of each animal’s life and they have found out that,
unlike humans on Earth, every animal on Rhomaar grows the same amount of
centimeters every year.
The scientists have given us information about the different animals heights but since the
planet is so far away we only received the following information. We need to act as
scientists to help them figure out the information they need.
TO DO:
1) Answer questions about ratios, rates and proportions of the animals.
2) Use charts and a graph to understand their rate of growth.
3) Draw a picture of what the animals look like.
Animals
Flickerbill: It is 36 centimeters tall when it is 4 years old.
Diggysee: It is 48 centimeters tall when it is 8 years old.
Tonypen: It is 60 centimeters tall when it is 10 years old.
Chucky: It is 35 centimeters tall when it is 7 years old.
Lightchee: It is 54 centimeters tall when it is 6 years old.
Stargazer: It is 64 centimeters tall when it is 8 years old.
Part One
Since there is so much work, lets split this up into groups.
Group #_________________
Animal:____________________
1) Write a ratio for your animals height in centimeters and the year of its life.
Ratio:
cm
years
Unit Rate=
cm
1 year
2) What is the constant of proportionality (unit rate)?
3) What was your animals height at 2 years?
4) What was your animals height at 5 years?
5) Write a proportion about your animals height.
6) Explain how you can figure out the height for your animal for any year of it’s life.
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
Part Two
1) Fill out the table for your animals height and # of years
(x) Years
1
2
3
4
5
6
7
8
(y)
Height
2) Put your information in a T-Chart
x (years)
y (height)
9
10
3) Use the information from above to plot the points of your animal on a graph.
a) What type of line did you graph? ___________________________________________________________
b) Explain what a point on the graph represents and explain why it is or is not a
proportional relationship.
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
4) Draw a picture of your animal on a separate piece of white paper.
Part Three
Get together with another group to compare and contrast your animals. Do your animals
have a proportional relationship?
1) Use the ratios, unit rates and proportions to justify your answer.
2) Create a table or graph to show if there is or is not a proportional relationship.
3) Draw your animals when they are at the same age to show their exact height.
4) Since you are a scientist, be ready to present your findings.
Animals of Rhomar
Points
Credit for specific aspects of performance should be given as follows:
Part 1
1. Ratios depend on animal chosen. 36/4, 48/6, 60/10, 35/7,
54/6 or 64/8 are all acceptable answers.
2. Unit ratio depends on animal chosen: 9cm/yr, 6 cm/yr, 6
cm/yr, 5 cm/yr, 9 cm/yr, 9 cm/cm are acceptable answers.
3. Answers depend on animal chosen: 18 cm, 12 cm, 12 cm, 10
cm, 18 cm, 16 cm are acceptable answers.
4. Answers depend on animal chosen: 45 cm, 30 cm, 30 cm, 25
cm, 45 cm, 40 cm are acceptable answers.
5. 1 ratio
2 ratios
A proportion of two ratios.
6. Key phrases to look for: “divide height by years”, “multiply by
years wanted”, or “convert to unit rate and multiply”.
Part 2
1. Values should be (year x unit rate). Answers will vary
depending on animal chosen.
2. Transferred values to t-table
Values transposed
Transferred correctly
3. Label both axis
a. “straight” or “unbending”
b. No, with no explanation
Yes, with no explanation
No, with wrong explanation
Yes, with wrong explanation.
Yes, with right explanation – key phrases might be: “ xcoordinate is the time”, “y-coordinate is height”, “height at a
certain year” are possible terms.
4. Animal Named
Pencil Sketched
Colored
Part 3
1. A ratio, rate and proportion is used to justify answer
2. Table or graph is used to justify whether proportional
relationship
3. Animals drawn at the exact height
Both animals have the correct age when the animals are the exact
height
4. At least 4 sentences to justify the findings
Total Points
Total
Points
1 pt.
1pt.
1 pt.
1 pt.
1 pt.
1 pt.
1 pt.
1 pt.
1 pt.
2 pts.
3 pts.
I pt. per
key phrase
3 pts.
1 pt. for
every 2
sets of
points.
5 pts.
1 pt.
2 pts.
1 pt.
1 pt.
1 pt.
1 pt.
2 pts.
2 pts.
3 pts.
2 pts.
2 pts.
3 pts.
1 pt.
2 pts.
2 pts.
5 pts.
3 points
3 points
3 points
3 points
2 points
4 points
6 points
4 points
4 points
40 points