Worksheet Grade 6 Science

Where Earth's Water Is Stored: A Kestrel Bend Water Model

A grade 6 science worksheet where students build a jar model of Earth's water, using percentages and residence times to see how little fresh water people can reach.

Grade: Grade 6
Subject: Science
Material: Worksheet
Time: 35 min
Prep: No prep
Materials: None

Standards

MS-ESS2-4 NGSS

Develop a model to describe the cycling of water through Earth's systems driven by energy from the sun and the force of gravity.

How this material aligns: Items 5 through 8 have students model the water cycle as water changing state and moving through the sky, ground, and ocean, driven by the sun and gravity.

All materials for MS-ESS2-4 →

6.RP.A.3 Common Core Math

Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations, including finding a percent of a quantity and converting measurement units.

How this material aligns: Items 1, 2, and 9 ask students to find a percent of a quantity, computing what part of a 1,000 mL and a 100 mL model stands for ocean and frozen water.

All materials for 6.RP.A.3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will calculate what part of a water model stands for oceans, ice, and fresh water using given percentages.
Students will explain why usable fresh water is only a small share of Earth's water.
Students will describe how the sun and gravity move water through the water cycle.

Vocabulary

Water cycle: The water cycle is the continuous movement of water between the oceans, the air, and the land. The same water evaporates, forms clouds, falls as rain or snow, and flows back to the ocean before the process repeats.
Evaporation: Evaporation happens when liquid water, often warmed by the sun, turns into an invisible gas called water vapor that rises into the air. It is how water leaves oceans, lakes, and puddles.
Groundwater: Groundwater is water that has soaked into the ground and fills the spaces between soil particles and cracks in rock underground. It is a large underground source of fresh water that wells and springs draw from.
Reservoir: A human-made lake, usually created by a dam, that stores water for later. Reservoirs supply cities and farms and help control floods.

Teacher overview

The sixth graders at Kestrel Bend Middle School build a jar model to show where all of Earth's water is stored. About 97% of Earth's water is in the oceans, about 2% is frozen in ice caps and glaciers, and less than 1% is fresh water that people can easily reach. This worksheet has students turn those shares into amounts in a model jar, then explain how water keeps moving through the water cycle.

Where Earth's Water Is Stored: A Kestrel Bend Water Model — Grade 6 Science

Name: ____________________________ Date: ______________

Student Worksheet

Use these facts for the whole page. About 97% of Earth's water is in the oceans. About 2% is frozen in ice caps and glaciers. Less than 1% is fresh water that people can easily use. The water cycle is driven by two things: energy from the sun and the force of gravity. A drop of water spends about 9 days in the air, but water deep underground can stay for hundreds or thousands of years.

The class fills a jar with 1,000 mL of water to stand for all of Earth's water. Ocean water is about 97% of the total. How many mL of the jar show ocean water?
Ice caps and glaciers hold about 2% of Earth's water. How many mL of the 1,000 mL jar show frozen water?
After you pour out the ocean water and the frozen water, how many mL are left in the jar to stand for all other water, such as lakes, rivers, groundwater, and water in the air?
Your answer to item 3 stands for every lake, river, and aquifer on Earth. Explain what this small amount shows about how much fresh water people have to share.
The sun's energy and gravity both move water. Which one causes liquid water to turn into vapor and rise into the air?
Which one, the sun or gravity, causes rain to fall and rivers to flow downhill?
A drop of water spends about 9 days in the air before it falls again. If a drop moved through the air 4 separate times, about how many days would it spend in the air in all?
Water deep underground can stay in place for hundreds of years. Explain why deep groundwater moves so much more slowly than water in the air.
The class wants a second, smaller model. This time 100 mL of water stands for all of Earth's water. How many mL would show the ocean?
In two or three sentences, explain what the jar model shows about how much of Earth's water people can drink, and why saving and cleaning water matters.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: 970 mL.
Ocean water is 97% of the total. 97% of 1,000 mL is 0.97 x 1,000 = 970 mL.
Answer: 20 mL.
Frozen water is 2% of the total. 2% of 1,000 mL is 0.02 x 1,000 = 20 mL.
Answer: 10 mL.
Start with 1,000 mL, then remove 970 mL of ocean and 20 mL of frozen water. 1,000 - 970 - 20 = 10 mL left for all other water.
Answer: Fresh water people can use is a very small part of all Earth's water.
The 10 mL from item 3 stands for every lake, river, aquifer, and cloud, and only part of that is fresh water people can reach. Accept any answer that says usable fresh water is a small share and must be shared and protected.
Answer: The sun.
Energy from the sun heats water and turns it into water vapor, which rises into the air. This step is called evaporation.
Answer: Gravity.
Gravity pulls rain down out of the clouds and pulls river water downhill toward lower ground and the ocean.
Answer: 36 days.
Each trip through the air is about 9 days. 4 trips is 9 x 4 = 36 days in all.
Answer: Deep groundwater moves slowly because it seeps through tiny spaces in soil and rock.
Water in the air is pushed by sun and wind and can move far in days, while underground water creeps through small pore spaces, so it can stay for years. Accept any answer describing slow movement through small spaces underground.
Answer: 97 mL.
Ocean water is 97% of the total. 97% of 100 mL is 0.97 x 100 = 97 mL.
Answer: Only a tiny part of Earth's water is fresh and easy to drink, so people should save it and keep it clean.
Accept any answer that connects the small "other water" amount from the model to the need to conserve and protect clean water.

Differentiation

Support

Give students a place-value hint that 1% of 1,000 mL is 10 mL, so 97% is 97 x 10 and 2% is 2 x 10. Provide a drawn jar with a scale marked in tenths so students can shade the ocean, frozen, and other-water shares before they calculate.

Extension

Ask students to design a third model in which 500 mL stands for all of Earth's water, and to find the ocean, frozen, and other-water amounts. Have them explain why the shares stay the same even when the jar size changes.

ELL supports

Pre-teach "ocean," "frozen," "fresh water," "evaporation," and "groundwater" with a simple labeled water-cycle picture. Allow students to answer items 4, 8, and 10 with a labeled drawing plus a short phrase instead of full sentences.