Grade 2 Science Week 10 | Student Textbook

Grade 2 | SCIENCE

WEEK 10 • STUDENT TEXTBOOK • DAYS 46–50

Read each lesson with a parent or teacher and study the worked example. Then answer the questions for that day in the Week 10 Practice Workbook.

Week 10 Student Textbook | Week 10 Practice Workbook | Week 10 Teacher Guide | Week 9 Student Textbook | Grade 2 index

Day 46: Where Is Water Found on Earth?

Water is found in many places on Earth: in oceans, lakes, rivers, ponds and streams, under the ground, and frozen as ice and snow.

Most of Earth’s water is in the ocean. Scientists report that about 97 out of every 100 parts of Earth’s water are in the ocean.

Worked example: Name two places where you can find water on Earth that are not the ocean.

Think of water on land: lakes and rivers.

Worked answer: A lake and a river (also pond, stream, underground or ice).

Day 47: Salt Water and Fresh Water

Ocean water is salt water. It is too salty for people to drink.

Lakes, rivers, ponds and the water under the ground are usually fresh water. People, many animals and most land plants need fresh water. Only a small part of Earth’s water is fresh.

Worked example: Is river water usually fresh or salty?

Rivers carry rain and melted snow from the land.
That water is fresh.

Worked answer: Fresh.

Day 48: Water as a Solid: Ice and Snow

Water can be a liquid or a solid. When water gets cold enough, it freezes into solid ice. Snow is also frozen water.

Some places on Earth are so cold that ice stays all year. A glacier is a huge, slow-moving body of ice on land. Very large sheets of ice cover Antarctica and Greenland. Scientists report that about 2 out of every 100 parts of Earth’s water are frozen in glaciers.

Worked example: Is a glacier made of liquid water or solid water?

A glacier is a huge body of ice.
Ice is solid water.

Worked answer: Solid water.

Day 49: A Model of Earth’s Water

A model can show amounts that are too big to see. Imagine all of Earth’s water divided into 100 equal parts.

About 97 parts would be ocean water. About 2 parts would be frozen in glaciers and ice. Only about 1 part would be all the rest: lakes, rivers, ponds, water under the ground and water in the air. Not all of that last part is easy to use. Some is deep underground, some is salty, and some is in the air.

Worked example: In the 100-piece model, how many pieces stand for the ocean?

The ocean holds about 97 out of 100 parts.

Worked answer: 97 pieces.

Day 50: Independent Check: Water on Earth

Today you will answer on your own.

Use what you learned this week: where water is found, fresh and salt water, and solid and liquid water.

Worked example: Is snow solid or liquid water?

Snow is frozen water.

Worked answer: Solid.