4th grade · Science · Unit 1 of 7
Wind, Water & Ice
How the land changes shape
What your child practices
How wind, water and ice break rock down (weathering) and carry it away (erosion), slowly changing the shape of the land, and how plants and windbreaks protect soil.
Minnesota K-12 Academic Standards benchmark: 4E.1.2.1.1; 4E.3.2.2.1 · how wind, water and ice change the land, and ways to lessen the harm
How we explain it
Children can open this short lesson before they practice.
- Weathering breaks rock into smaller pieces. Erosion carries them away.
- Water in a crack freezes, expands and splits the rock.
- Waves wear away cliffs, and glaciers scrape and carve rock as they slowly move.
- Most of these changes take many years.
Example: Put in order: the rock splits, rain fills a crack, the water freezes. First, rain fills a crack. Then the water freezes and expands. Last, the rock splits. Answer: rain fills a crack → the water freezes → the rock splits
Wind, Water & Ice in Minnesota
In the Minnesota K-12 Academic Standards, this is unit 1 of 7 in 4th grade Science, before Pushes, Pulls & Forces.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A valley shaped like a V was most likely carved by…
🏞️- a glacier
- a river
- the wind
a river
Hint: Rivers cut narrow V-shaped valleys. Glaciers scrape out wide U-shaped valleys.
Question 2
Farmers plant rows of trees beside their fields. How does this help?
🌳- the trees slow the wind, so less soil blows away
- the trees make the wind stronger
- the trees pull soil up into the sky
the trees slow the wind, so less soil blows away
Hint: Trees block the wind. Slower wind can't carry away as much soil.
Question 3
Rocks in a river are often smooth and round. Why?
🪨- they tumble and rub together in the water for a long time
- they grow that way
- people polish them
they tumble and rub together in the water for a long time
Hint: Moving water knocks the rocks into each other. Their sharp edges slowly wear off.
Question 4
What is changing the land: wind, water or ice?
Sort into: 🌬️ wind · 🌊 water · 🧊 ice
- 🪨blowing sand wears a rock smooth
- ❄️frozen water splits a rock
- 🏔️a glacier carves a valley
- 🏞️a river carves a canyon
- 🏜️blows sand into dunes
- 🌧️rain washes soil down a hill
🌬️ wind: blowing sand wears a rock smooth, blows sand into dunes · 🌊 water: a river carves a canyon, rain washes soil down a hill · 🧊 ice: frozen water splits a rock, a glacier carves a valley
Hint: Wind blows sand and dust. Water flows, splashes and washes things away. Ice freezes in cracks, and glaciers scrape the land.
Question 5
Breaking rock into smaller pieces is called…
🪨- weathering
- melting
- erosion
weathering
Hint: Weathering breaks rock down. Wind, water and ice can all do it.
Question 6
How does a river make a canyon? Put the steps in order.
- 🏞️a river flows over rock
- ⏳over many years, the river cuts deeper
- 💧the water carries away tiny bits of rock
- 🏜️a deep canyon forms
a river flows over rock → the water carries away tiny bits of rock → over many years, the river cuts deeper → a deep canyon forms
Hint: Moving water carries away tiny bits of rock. Over many, many years, the river cuts deeper and deeper.