Data and Graphs: Recording Life Cycle Changes
Learn
When scientists observe life cycles, they collect data. Data are facts and numbers about what we observe. We can organize data in tables and show it in graphs to help us see patterns.
What Is Data?
Data is information we collect. When studying life cycles, data might include:
- How tall a plant grows each week
- How many days until a caterpillar becomes a chrysalis
- How many leaves a plant has
- The size of a tadpole over time
Using Tables to Organize Data
A table puts information in rows and columns so it is easy to read. Tables help us:
- Keep our data organized
- Compare information from different days
- Find information quickly
Using Graphs to Show Data
A graph is a picture that shows data. Graphs help us:
- See patterns and changes
- Compare different things
- Understand data at a glance
Types of Graphs for Second Graders
- Picture Graph: Uses pictures or symbols to show data
- Bar Graph: Uses bars to compare amounts
- Line Graph: Shows how things change over time
Examples
Example 1: Data Table for Plant Growth
| Week | Height (cm) | Number of Leaves |
|---|---|---|
| Week 1 | 2 cm | 2 |
| Week 2 | 5 cm | 4 |
| Week 3 | 9 cm | 6 |
| Week 4 | 14 cm | 8 |
What we can learn: The plant grew taller each week. It also grew more leaves over time.
Example 2: Picture Graph - Butterfly Life Cycle Stages
How many days in each stage?
Egg: * * * * (4 days)
Caterpillar: * * * * * * * * * * * * * * (14 days)
Chrysalis: * * * * * * * * * * (10 days)
Butterfly: * * * * * * * * * * * * * * * * * * * * (20+ days)
Each * = 1 day
Example 3: Reading a Bar Graph
Plant Heights in Our Class Garden
Sunflower: |||||||||| (10 cm)
Bean plant: |||||||| (8 cm)
Tomato: |||||| (6 cm)
Marigold: |||| (4 cm)
Each | = 1 cm
Question: Which plant is tallest?
Answer: The sunflower is tallest at 10 cm.
Practice
Use the data table and answer the questions.
Tadpole Growth Data
| Week | Body Length (cm) | Tail Length (cm) |
|---|---|---|
| Week 1 | 1 | 2 |
| Week 2 | 2 | 3 |
| Week 3 | 3 | 3 |
| Week 4 | 4 | 2 |
1. How long was the tadpole's body in Week 1?
2. In which week was the tail the longest?
3. What happened to the body length from Week 1 to Week 4?
4. What happened to the tail from Week 3 to Week 4?
5. What is data?
6. Why do scientists use tables?
7. A picture graph uses _____ to show data.
8. Look at the plant growth table in the Examples. How many leaves did the plant have in Week 3?
9. Which type of graph is best for showing how something changes over time?
10. A student measured a bean plant every day. On Monday it was 3 cm. On Friday it was 7 cm. How much did it grow?
11. What can graphs help us see?
12. In the tadpole table, which week shows the body and tail were the same length?
Check Your Understanding
Think about these questions to make sure you understand data and graphs.
- Can you explain what data is in your own words?
- Why is it helpful to put data in a table?
- What is one thing you can learn from a graph?
- What kind of data would you collect if you were studying a growing sunflower?
Next Steps
- Practice making your own data table for something you observe at home
- Try drawing a picture graph to show your data
- Continue to the next lesson to learn how to write about your findings