Science · Unit 2 · Weeks 7–12 · 40–45 min

Scoring Guide: Magnet Design & Ecosystems

44 points total

Part 1: Designing with Magnets

10 points

Read Ravi's design problem. Use it and the table to answer questions 1 to 4.

1.
Write one criterion and one constraint from Ravi's problem.
(2 pts)
Answer: Criterion: any one of the boats must not touch, or they must float upright. Constraint: any one of only 2 magnets, only tape, or 30 minutes.
2.
How should Ravi place the two magnets so the boats push apart? Use the word poles.
(2 pts)
Answer: Put one magnet on each boat with the same poles facing each other (north toward north or south toward south), because like poles repel.
3.
Which design is the best one for Ravi to improve? Tell why the other two do not fit his rules.
(3 pts)
Answer: Design B. Design A tips over, so it misses a criterion. Design C uses 4 magnets, so it breaks the 2-magnet constraint. Design B floats and follows the rules; it only needs to stop touching.
4.
In Design B, the boats touched 3 times. What do engineers call the place or moment where a design stops working? Name one change Ravi could make and test next.
(3 pts)
Answer: A failure point. Answers vary for the change. Look for: one sensible change, such as using stronger magnets, lining the magnets up at the same height, or stopping the boats from turning so opposite poles do not face each other; then test it again 10 times.

Scoring: Item 1: 1 point for a criterion, 1 point for a constraint. Item 2: 1 point for same (like) poles facing, 1 point for 'repel' or 'push apart'. Item 3: 1 point for B, 1 point for each design correctly ruled out. Item 4: 1 point for 'failure point', 2 points for a change that fits the problem (1 point if the change breaks a rule, such as adding a third magnet).

Reteach if needed: Week 7, Week 9. Week 7 Days 1–5 (define a magnet problem, criteria and constraints, compare designs, find failure points and improve); Week 9 Day 3 (solving a design problem with magnets).

Part 2: Planning a Fair Test

12 points

Read about Mila's investigation. Use the table to answer questions 5 to 10.

5.
What is the one thing Mila changes?
(1 pt)
Answer: the number of rubber bands (how strong the push is)
6.
List two things Mila must not change from one trial to the next.
(2 pts)
Answer: Any two: the same car, the same floor, pulling the car back the same distance, the same launcher, measuring the same way.
7.
What is the middle value for 2 rubber bands?
(1 pt)
Answer: 78 cm
8.
Make a bar graph of the middle value for each number of rubber bands. Give it a title and label both sides.
(3 pts)
Answer: Bars: 1 band = 40 cm, 2 bands = 78 cm, 3 bands = 107 cm, with a title, labeled axes and an even scale.
9.
Use the pattern to predict: about how far would the car roll with 4 rubber bands? Explain your prediction.
(2 pts)
Answer: Answers vary. Look for: farther than 107 cm (about 130 to 145 cm), because each extra rubber band made the car roll farther.
10.
Write Mila's conclusion. Does a stronger push make the car roll farther? Use two numbers from the table.
(3 pts)
Answer: Yes. With 1 rubber band the car rolled about 40 cm, and with 3 rubber bands it rolled about 107 cm. A stronger push made the car roll farther.

Scoring: Item 5: 1 point. Item 6: 1 point for each thing kept the same. Item 7: 1 point. Item 8: 1 point for three bars in the right order of height, 1 point for title and labels, 1 point for an even scale. Item 9: 1 point for 'farther than 107 cm', 1 point for using the pattern. Item 10: 1 point for 'yes', 1 point for each correct number from the table (any trial or middle value).

Reteach if needed: Week 8, Week 9. Week 8 Days 1–5 (testable questions, one changed variable, middle values, bar graphs, conclusions with evidence); Week 9 Days 1 and 3 (unbalanced forces and using patterns to predict).

Part 3: Ecosystems & Habitats

12 points

Read each question. Use the table for question 13.

11.
Write P for producer, C for consumer or D for decomposer. ___ a cattail plant ___ a heron ___ bacteria that break down dead leaves in the mud
(2 pts)
Answer: P, C, D
12.
Which one can make more of its own kind?
(1 pt)
Answer: a fern
13.
In which place do these ferns survive well, survive less well and not survive at all? Make an argument. Claim: ____ Evidence: ____ Reasoning: ____
(6 pts)
Answer: Answers vary. Look for: Claim: these ferns survive well in the damp, shady woods, less well on the sunny lawn edge and not at all in the dry gravel lot. Evidence: 11 of 12 lived in the woods, 5 of 12 on the lawn edge and 0 of 12 in the gravel. Reasoning: a habitat must meet a living thing's needs; these ferns need damp shade, so the drier and sunnier the place, the fewer survived.
14.
Many desert snakes hide under rocks during the hottest part of the day. Is this a physical or a behavioral adaptation? How does it help them survive?
(2 pts)
Answer: Behavioral. It keeps them out of the heat so they do not get too hot.
15.
An owl nests in a hollow tree. Which need does the hollow tree meet?
(1 pt)
Answer: shelter

Scoring: Item 11: 2 points for all three right, 1 point for two. Item 12: 1 point. Item 13: Claim: 2 points for a clear answer to the question, 1 point for a partly correct claim. Evidence: 2 points for two facts or numbers from the table or text, 1 point for one. Reasoning: 2 points for a science idea that links the evidence to the claim, 1 point for a link with a gap or a restated claim. Spelling does not count. If your child can say it but not write it, write their words down and score them. Item 14: 1 point for 'behavioral', 1 point for how it helps. Item 15: 1 point.

Reteach if needed: Week 10, Week 11. Week 10 Days 1–4 (ecosystems, the living checklist, producers, consumers and decomposers); Week 11 Days 1–4 (habitat needs, world habitats, physical and behavioral adaptations).

Part 4: Food Chains & Food Webs

10 points

Read the prairie food web. Each arrow points from the food to the eater.

16.
Use the prairie web. Write a food chain with 4 living things in it.
(2 pts)
Answer: Either grass → mouse → snake → hawk, or grass → grasshopper → meadowlark → hawk.
17.
A sickness kills most of the prairie dogs. Which two animals in the web lose some of their food? Name another food each one can still eat.
(2 pts)
Answer: The hawk and the coyote. The hawk can still eat snakes or meadowlarks; the coyote can still eat mice.
18.
A very dry summer kills half of the grass. Predict what happens to the grasshoppers and then to the meadowlarks. Use 'because.'
(3 pts)
Answer: There may be fewer grasshoppers because they have less grass to eat, and then fewer meadowlarks (or hungrier meadowlarks that move away) because they have fewer grasshoppers to eat.
19.
A town is building houses on part of the prairie. Plan A: save a strip of prairie along the creek and plant prairie grasses. Plan B: plant a mowed lawn and put up birdhouses. Which plan would help more animals in this web? Make a claim and give a reason.
(3 pts)
Answer: Plan A. Answers vary. Look for: the prairie grasses feed the grasshoppers, mice and prairie dogs, and those animals feed the meadowlarks, snakes, hawks and coyotes, so more of the web keeps its food and shelter; a mowed lawn and birdhouses help only a few birds.

Scoring: Item 16: 2 points for a correct chain with 4 living things and arrows the right way, 1 point if the arrows point the wrong way. Item 17: 1 point for each animal named with another food it can still eat. Item 18: 1 point for fewer grasshoppers with a reason, 1 point for the effect on meadowlarks, 1 point for using 'because' to link them. Item 19: 1 point for Plan A, 2 points for a reason that uses the food web (1 point for a reason that does not use the web).

Reteach if needed: Week 12. Week 12 Days 1–4 (food chains, energy from the sun, food webs, predicting what happens when the habitat changes and judging solutions).

Score box

Part	Points earned	Possible
1. Designing with Magnets		10
2. Planning a Fair Test		12
3. Ecosystems & Habitats		12
4. Food Chains & Food Webs		10
Total		44

Level: Enter points to see the level.

D · Developing: 0–21
A · Approaching: 22–30
P · Proficient: 31–39
E · Exceeding: 40–44