Grade 2 | SCIENCE
WEEK 3 • STUDENT TEXTBOOK • DAYS 11–15
Read each lesson with a parent or teacher and study the worked example. Then answer the questions for that day in the Week 3 Practice Workbook.
Week 3 Student Textbook | Week 3 Practice Workbook | Week 3 Teacher Guide | Week 2 Student Textbook | Week 4 Student Textbook | Grade 2 index
Day 11: What Plants Need to Grow
Plants are living things. To grow well, most plants need water, light, air and space. Their roots also take in nutrients from the soil.
Plants use light to make their own food in their leaves. A plant that is missing one of its needs may grow slowly, turn yellow or droop.
Worked example: A plant’s leaves are drooping and the soil is dry. Which need is probably missing?
- Look at the clues: drooping leaves and dry soil.
- Dry soil means the roots are not getting water.
Worked answer: Water is probably missing.
Day 12: Planning a Fair Test
Scientists use a fair test to find out what a plant needs. In a fair test, you change only one thing and keep everything else the same.
To test water, give two plants the same soil, the same light and the same pot. Water one plant and do not water the other. The one thing you change is called the variable.
Worked example: Ana wants to test whether bean plants need light. What should she change, and what should stay the same?
- The thing being tested is light, so light is the variable.
- One plant gets light; the other is kept in the dark.
- Water, soil, pot size and type of plant stay the same.
Worked answer: Change only the light. Keep the water, soil, pot and kind of plant the same.
Day 13: Reading Test Results
After a test, scientists record what they observe. A results table shows the data in rows and columns so it is easy to compare.
In Leo’s table, each column is one plant and each row is one day. Look down a column to follow one plant over time. Look across a row to compare the plants on the same day.
Worked example: A results table shows Plant X at 2 cm on Day 1 and 6 cm on Day 10. How much did it grow?
- Find the starting height: 2 cm.
- Find the ending height: 6 cm.
- Subtract: 6 – 2 = 4.
Worked answer: Plant X grew 4 cm.
Day 14: Too Much or Too Little
Plants need the right amount of water. Too little water makes a plant dry and droopy. Too much water can fill the soil so the roots cannot get air, and the roots may rot.
Different plants need different amounts. A cactus needs very little water. A fern needs damp soil.
Worked example: A plant sits in a pot with no hole in the bottom, and the soil is always soggy. What could go wrong?
- Extra water cannot drain out.
- Soggy soil keeps air away from the roots.
- Roots without air can rot.
Worked answer: The roots could rot from too much water.
Day 15: Independent Check: Plants and Fair Tests
Today you will read a new test and answer on your own.
Use what you learned: what plants need, how a fair test changes only one thing, and how to read results.
Worked example: Which need is missing from a plant kept in a dark closet?
- A dark closet has no sunlight.
- Plants need light to make food.
Worked answer: Light.
Week 3 Student Textbook | Week 3 Practice Workbook | Week 3 Teacher Guide | Week 2 Student Textbook | Week 4 Student Textbook | Grade 2 index