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Inside and Outside is a free printable Grade 4 science worksheet on telling a living thing's internal structures from its external ones, aligned to NGSS performance expectation 4-LS1-1. It prints 3 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.

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One paper per student

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All 25 sets ask different questions.

Inside and Outside

4-LS1-1

NameDate

Sort each structure into inside or outside.

1.Sort each one: Outside structure or Inside structure?

Sort: A stomach, which breaks down food, Tiny tubes inside a stem, which carry water to the leaves, A rose's thorns, which keep animals off the stem, A fish's scales, which protect its skin

Outside structureInside structure
2.Sort each one: Outside structure or Inside structure?

Sort: A rabbit's long ears, which catch faint sounds, Lungs, which take in air, A brain, which controls the body, A cactus's spines, which stop animals eating it

Outside structureInside structure
3.Sort each one: Outside structure or Inside structure?

Sort: A tree's bark, which protects the trunk, A bird's feathers, which keep it warm, A heart, which pumps blood around the body, A skeleton, which holds the body up

Outside structureInside structure

LessonPrint · 4-LS1-1 · Set 1 · free to copy for classroom use

Answer key — Inside and Outside

Set 1. Prints on its own sheet.

  1. 1.1. A fish's scales, which protect its skin — Outside structure 2. A rose's thorns, which keep animals off the stem — Outside structure 3. A stomach, which breaks down food — Inside structure 4. Tiny tubes inside a stem, which carry water to the leaves — Inside structure
  2. 2.1. A brain, which controls the body — Inside structure 2. A cactus's spines, which stop animals eating it — Outside structure 3. A rabbit's long ears, which catch faint sounds — Outside structure 4. Lungs, which take in air — Inside structure
  3. 3.1. A bird's feathers, which keep it warm — Outside structure 2. A heart, which pumps blood around the body — Inside structure 3. A skeleton, which holds the body up — Inside structure 4. A tree's bark, which protects the trunk — Outside structure

Questions about Inside and Outside

What does the Inside and Outside worksheet cover?

It practices telling a living thing's internal structures from its external ones — 3 questions for Grade 4, all on NGSS 4-LS1-1: Argue that inside and outside body parts help a living thing survive and grow. The instruction to students is “Sort each structure into inside or outside”, and the answer key follows on the next sheet.

Which NGSS performance expectation does Inside and Outside practice?

4-LS1-1, under Life Science for Grade 4. The published performance expectation reads: “Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.” The worksheet assesses that performance expectation rather than a paraphrase of it.

What age or grade is this worksheet for?

Inside and Outside is written for Grade 4, typically ages 9-10. It is one of the sheets on 4-LS1-1, so it suits any student working at that standard — including older students revisiting it and younger ones working ahead.

Does Inside and Outside come with an answer key?

Yes. All 3 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 Inside and Outside 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 Inside and Outside free to print and photocopy?

Yes. Inside and Outside, 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.

Is there a lesson plan to teach 4-LS1-1?

Yes — “Inside and Outside” is a 55-minute Grade 4 plan for 4-LS1-1, timed section by section, with the misconceptions to expect and an exit ticket. Inside and Outside is the practice that follows it.

More practice for 4-LS1-1

Argue that inside and outside body parts help a living thing survive and grow.

Teaching this next? Inside and Outside is the 55-minute plan for it, with the misconceptions to expect.

All Grade 4 worksheets

Last reviewed 2026-09-05. Aligned to 4-LS1-1 of the Next Generation Science Standards.