Ahava~Love Assembly

Grade 2 Science Week 10 | Teacher Guide

Grade 2 | SCIENCE

WEEK 10 • TEACHER GUIDE AND ANSWER KEY • DAYS 46–50

Read each lesson aloud with the child and model the worked example before practice. Do not show this key during practice. Accept oral, drawn or written answers where the child cannot yet write the whole answer. On Day 50, read aloud if needed but give no hints.

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?

Standard: Grade 2 Science Standard 9, 2.9

Practice record: Where water is, printed on the Week 10 Practice Workbook.

Worked example: Name two places where you can find water on Earth that are not the ocean. Worked answer: A lake and a river (also pond, stream, underground or ice).

  1. In the ocean.
  2. The glacier and the snow on a mountain.
  3. The ocean covers most of Earth’s surface, and ocean water looks blue from space. Accept any answer that connects blue to the large amount of ocean water.

Teaching note: Show a globe and let the child feel how much of it is blue.

Day 47: Salt Water and Fresh Water

Standard: Grade 2 Science Standard 9, 2.9

Practice record: Fresh or salty?, printed on the Week 10 Practice Workbook.

Worked example: Is river water usually fresh or salty? Worked answer: Fresh.

  1. The ocean.
  2. Any two of: lake, water under the ground, glacier ice.
  3. Ocean water is too salty to drink. Only a small part of Earth’s water is fresh, and people need fresh water to drink and grow food. Accept any answer about fresh water being the small part people need.

Teaching note: Let the child taste a cup of water with a pinch of salt stirred in, then plain water, to feel the difference. Do not drink large amounts of salt water.

Day 48: Water as a Solid: Ice and Snow

Standard: Grade 2 Science Standard 9, 2.9

Practice record: Ice melt test, printed on the Week 10 Practice Workbook.

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

  1. The ice cube in the sunny window.
  2. The one in the freezer.
  3. Warmth melts ice into liquid water. The warmest place melted it fastest, and the cold freezer kept it solid. Accept any answer linking warmth to melting.

Teaching note: Repeat the ice melt test at home with three cubes of the same size. Times will vary; the order (sun fastest, freezer none) should match.

Day 49: A Model of Earth’s Water

Standard: Grade 2 Science Standard 9, 2.9

Worked example: In the 100-piece model, how many pieces stand for the ocean? Worked answer: 97 pieces.

  1. 2 pieces.
  2. 1 piece.
  3. Only a small part. The ocean pile is salty and the ice pile is frozen. The water people drink comes from the 1-piece pile, and even some of that piece is deep underground, salty or in the air. So usable fresh water is only a small part of Earth’s water. Accept any answer that the usable part is small.

Teaching note: These numbers are rounded from the sources listed below (about 97 percent ocean and about 2 percent glaciers). The single piece is a Grade 2 simplification: it is not all drinkable or easy to reach, and the lesson says so. Use the observation checklist below.

Hands-on task observation checklist (Model Earth’s water with 100 pieces). Check each item you observe. Four or five items shows the child met the task goal; two or three means repeat the task with support.

  • ☐ Child counted 100 pieces accurately.
  • ☐ Piles show 97, 2 and 1.
  • ☐ Each pile is labeled correctly.
  • ☐ Child identified the ocean as holding most of Earth’s water.
  • ☐ Child explained that usable fresh water is only a small part of Earth’s water.

Day 50: Independent Check: Water on Earth

Standard: Grade 2 Science Standard 9, 2.9

Practice record: Text: A Trip to the Mountains, printed on the Week 10 Practice Workbook.

Worked example: Is snow solid or liquid water? Worked answer: Solid.

  1. The snow on the mountain top.
  2. The stream or the lake.
  3. Warmer spring weather melted the snow into liquid water, and the melted water ran down into the stream. Accept any answer linking melting snow to more stream water.

Teaching note: Independent check: read the text aloud if needed, but give no hints.

Sources

NOAA National Ocean Service, How much water is in the ocean? | U.S. Geological Survey, How much of the Earth’s water is stored in glaciers?

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

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