Wearing the Rock Away
A 55-minute Grade 4 lesson on measuring the effects of weathering and the rate of erosion by water, ice, wind and vegetation.
Wearing the Rock Away is a free 55-minute Grade 4 science lesson plan for Common Core standard 4-ESS2-1 — measure what water, ice, wind or plants do to rock and soil. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 4
- Length:
- 55 minutes
- Standard:
- 4-ESS2-1
Grade 4 · Earth and Space Science
4-ESS2-1
Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation.
Objective
Students will be able to measure and compare how fast different agents wear rock away.
Students are successful when they can
- Measures a rate rather than describing an effect.
- Compares four agents on the same starting mass.
- Names which wore away most and by how much.
What you need
- Chalk or soft rock samples, balance, jars, a freezer, a fan and sand, seed trays
- A results table with starting and finishing masses
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up
5 min- Show a weathered gravestone and a sharp new one.
- Ask what has been happening, and how fast.
Teach — measure the rate
14 min- Weigh four identical chalk samples: 50 g each.
- Set up four jars: shaken in water, frozen and thawed, blown with sand, packed with roots.
- Say why the starting mass must be the same: otherwise the losses cannot be compared.
- After a week, reweigh and calculate the loss for each.
- Read the results: freezing and thawing lost most, at 6.8 g.
- Explain that one: water in cracks expands as it freezes and pushes the rock apart.
“How much did it lose, and over how long?”
Investigate — set up and measure
19 min- Groups weigh four identical samples and set up the four treatments.
- They record starting masses and the date.
- They reweigh after the set period and calculate each loss.
- They rank the four agents and write the fastest with its figure.
Independent practice
14 min- Students complete the 'Wearing the Rock Away' page.
- Check comparisons use the measured losses.
Close
3 min- Ask which agent is working on the school building right now.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Describes weathering without measuring it.
Why: It obviously happened.
Fix: The standard asks for measurements. How much, over how long?
Uses samples of different sizes.
Why: They were the rocks available.
Fix: Equal starting masses, or the losses mean nothing.
Thinks only water weathers rock.
Why: Water is the obvious agent.
Fix: Run all four jars. Ice beat water in this test.
If they are not there yet
- Two treatments rather than four.
- A table with starting masses filled in.
If they finish early
- Predict the loss over a year and say what could go wrong with that prediction.
- Test whether harder rock loses less.
- Explain why north-facing crags shed more fragments.
Exit ticket
Four identical chalk samples were treated for a week. Freezing and thawing lost 6.8 g and roots lost 1.4 g. What does that show?
What to look for: Freezing and thawing wore the chalk away fastest, with a measured rate for each agent. A description with no figures means the measurement step is missing.
Printable practice for 4-ESS2-1
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Wearing the Rock AwayLook at the measurements, then answer.
Questions about Wearing the Rock Away
How long does the Wearing the Rock Away lesson take?
55 minutes, split across 5 timed sections: warm-up 5 min, teach 14 min, investigate 19 min, independent practice 14 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Wearing the Rock Away teach?
4-ESS2-1 — 4-ESS2-1, Earth and Space Science for Grade 4: “Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation.” In plain terms, measure what water, ice, wind or plants do to rock and soil.
What do I need to teach this lesson?
Chalk or soft rock samples, balance, jars, a freezer, a fan and sand, seed trays, a results table with starting and finishing masses and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: describes weathering without measuring it; uses samples of different sizes and thinks only water weathers rock. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Four identical chalk samples were treated for a week. Freezing and thawing lost 6.8 g and roots lost 1.4 g. What does that show?.” Freezing and thawing wore the chalk away fastest, with a measured rate for each agent. A description with no figures means the measurement step is missing. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Wearing the Rock Away?
Yes — 1 printable 4-ESS2-1 worksheet, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Wearing the Rock Away free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 8 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-08. Aligned to 4-ESS2-1 of the Next Generation Science Standards.