Three Rock Pools is a free printable Grade 3 science worksheet on using rock-pool counts to argue which sea creatures survive well where, aligned to NGSS performance expectation 3-LS4-3. It prints 7 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two students in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 1 of 25 · the same problems every time you open this link.
Counts the class made in three rock pools at low tide: one high on the shore, one in the middle and one near the sea.
WHAT WE COUNTED
High pool (out of the sea for most of the day): 30 barnacles, 6 limpets, some green seaweed, no starfish, no kelp
Middle pool: 12 limpets, 9 sea anemones, 4 crabs, brown seaweed, no kelp
Low pool (covered by the sea for all but an hour a day): 5 starfish, 11 sea anemones, 6 crabs, kelp, 3 small fish
The high pool's water was the warmest, and its level dropped most in the sun.
We counted for ten minutes at each pool.
1. Why count for ten minutes at each pool?
2. What does this survey not tell you?
3. How many starfish were in the low pool?
4. Where was the kelp found?
2.Why does an anglerfish have a glowing lure on its head?
A.To scare the sun away
B.To attract prey in the dark deep sea, where no sunlight reaches
C.To keep itself warm
3.How can a seal live in icy seas?
A.It never gets wet
B.A thick layer of fat under its skin keeps it warm
C.It lives on land all year
4.Why do some animals in the deep sea have no working eyes?
A.There is no light to see by down there
B.The water is too salty for eyes
C.They are always asleep
5.What would happen to a kelp forest if the sea became very cloudy?
A.The kelp would get less light and grow less well
B.Nothing would change
C.The kelp would grow faster
6.Why can mussels and barnacles live where the waves crash?
A.Waves cannot reach them
B.They swim away from every wave
C.They are fixed tight to the rocks, and the waves bring them food
7.Why does kelp grow only in shallow water?
A.It is too heavy for deep water
B.It cannot swim
C.It needs sunlight, which cannot reach the deep sea
LessonPrint · 3-LS4-3 · Set 1 · free to copy for classroom use
Answer key — Three Rock Pools
Set 1. Prints on its own sheet.
1.1. So each pool was searched for the same time and the counts can be compared. 2. It does not tell you what lives in the pools at high tide. 3. 5 starfish. 4. Only in the low pool.
2.To attract prey in the dark deep sea, where no sunlight reaches
3.A thick layer of fat under its skin keeps it warm
4.There is no light to see by down there
5.The kelp would get less light and grow less well
6.They are fixed tight to the rocks, and the waves bring them food
7.It needs sunlight, which cannot reach the deep sea
Questions about Three Rock Pools
What does the Three Rock Pools worksheet cover?
It practices using rock-pool counts to argue which sea creatures survive well where — 7 questions for Grade 3, all on NGSS 3-LS4-3: Argue that a habitat suits some living things, suits others less, and suits some not at all. The instruction to students is “Read the record, then answer the questions”, and the answer key follows on the next sheet.
Which NGSS performance expectation does Three Rock Pools practice?
3-LS4-3, under Life Science for Grade 3. The published performance expectation reads: “Construct an argument with evidence that in a particular habitat some organisms can survive well, some survive less well, and some cannot survive at all.” The worksheet assesses that performance expectation rather than a paraphrase of it.
What age or grade is this worksheet for?
Three Rock Pools is written for Grade 3, typically ages 8-9. It is one of the sheets on 3-LS4-3, so it suits any student working at that standard — including older students revisiting it and younger ones working ahead.
Does Three Rock Pools come with an answer key?
Yes. All 7 answers are generated from the same problems as the questions, so the key cannot drift out of step with the sheet. It starts on a fresh sheet of paper, after the questions, so it is not handed out with the class by accident.
How many different versions of Three Rock Pools can I print?
25 — one per student, and all 25 ask different questions. Set 1 downloads the whole class as a single PDF. Every version is fixed to its own address, so a sheet printed today holds the same problems when you reopen it next week.
Is Three Rock Pools free to print and photocopy?
Yes. Three Rock Pools, its answer key and its 25 versions are free to print and photocopy for your own class, with no account, no email capture and no subscription at the download step. Please do not resell them or republish them as your own.
More practice for 3-LS4-3
Argue that a habitat suits some living things, suits others less, and suits some not at all.