Grade: Grade 5 Subject: Science Unit: Ecosystems & Energy Flow SAT: ProblemSolving+DataAnalysis ACT: Science

Data and Graphs

Learn

Scientists use data tables and graphs to organize observations about ecosystems. These tools help us see patterns, make comparisons, and communicate findings to others. In this lesson, you will learn how to collect ecosystem data and display it effectively.

Why Do Scientists Use Graphs?

Graphs turn numbers into pictures, making it easier to see patterns and trends. A graph can show at a glance what might take many sentences to explain. For ecosystem studies, graphs help us understand how populations change over time and how organisms interact.

Organizing Data in Tables

Before creating a graph, scientists organize their data in data tables. A good data table has:

  • A clear title describing what was measured
  • Column headers with labels and units
  • Data organized in rows and columns
  • Numbers recorded accurately

Example: Pond Ecosystem Organism Count

Organism Role in Ecosystem Week 1 Week 2 Week 3 Week 4
Algae (clumps) Producer 45 52 48 55
Water Snails Primary Consumer 30 35 38 42
Small Fish Secondary Consumer 15 17 19 20
Large Fish Tertiary Consumer 5 5 6 6

Types of Graphs for Ecosystem Data

Bar Graph

Uses rectangular bars to compare different categories. The height of each bar shows the quantity.

Best for: Comparing different organisms at one point in time

Line Graph

Uses points connected by lines to show how something changes over time.

Best for: Showing population changes over weeks or months

Pie Chart

A circle divided into slices showing parts of a whole (percentages).

Best for: Showing what percentage of organisms are producers vs. consumers

Pictograph

Uses pictures or symbols to represent data. Each symbol equals a certain number.

Best for: Making data visually engaging for presentations
Choosing the Right Graph: Ask yourself: "Am I comparing categories (bar graph), showing change over time (line graph), or showing parts of a whole (pie chart)?" The question you want to answer determines the best graph type.

Interactive Graph Builder

Enter population data and see it displayed as a bar graph!

Build Your Own Bar Graph

Enter the number of organisms found in an ecosystem to create a bar graph.

Enter Data

Ecosystem Population Graph

50
Plants
35
Insects
15
Birds
5
Foxes

Reading Line Graphs

Line graphs show how data changes over time. The x-axis (horizontal) shows time, and the y-axis (vertical) shows the quantity measured.

Rabbit Population Over 6 Months

50 40 30 20 10 0
Jan Feb Mar Apr May Jun

This graph shows the rabbit population increasing from about 10 in January to nearly 45 in June. The upward trend suggests favorable conditions with plenty of food and few predators.

Interpreting Trends

  • Increasing trend: Line goes up - population growing
  • Decreasing trend: Line goes down - population declining
  • Stable/flat: Line is mostly horizontal - population steady
  • Fluctuating: Line goes up and down - population varies

Examples

Example 1: Analyzing a Data Table

Forest Bird Count by Season

Bird Species Spring Summer Fall Winter
Robins 45 60 30 5
Cardinals 20 25 22 18
Blue Jays 15 20 18 12

Analysis Questions:

  1. Which bird has the highest population in summer? Robins (60)
  2. Which bird population stays most stable year-round? Cardinals (range of only 7)
  3. What might explain the robin population drop in winter? Many robins migrate south for winter

Example 2: Creating a Graph from Data

A scientist collected data on grasshopper populations over 5 weeks:

Week 1 2 3 4 5
Grasshoppers 20 35 55 70 85

Best graph type: Line graph (shows change over time)

Trend: Increasing - the grasshopper population is growing each week

Possible explanation: Warm weather and abundant plant food are supporting population growth

Practice

Answer these questions about data tables and graphs.

1 Which type of graph would be BEST for showing how a deer population changed over 12 months?
A Pie chart
B Bar graph
C Line graph
D Pictograph
2 A data table shows that producers have a count of 500, primary consumers have 50, and secondary consumers have 5. What pattern does this show?
A There are more consumers than producers
B Energy decreases as you move up the food chain
C All organisms have equal populations
D Secondary consumers produce the most energy
3 On a line graph, the line goes steadily downward from left to right. What does this indicate?
A The population is increasing
B The population is staying the same
C The population is decreasing
D No data was collected
4 What information should ALWAYS be included in a data table?
A Colors and pictures
B Title, labels, and units
C Only numbers, nothing else
D The scientist's name
5 A bar graph shows butterflies at 40, bees at 35, and beetles at 25. Which organism has the largest population?
A Bees
B Beetles
C Butterflies
D They are all equal
6 Why might scientists collect data over multiple weeks instead of just one day?
A Because they are bored
B To identify trends and patterns over time
C Because data from one day is always wrong
D To use more paper
7 If a pie chart shows 60% producers, 30% primary consumers, and 10% secondary consumers, which group makes up the majority?
A Secondary consumers
B Primary consumers
C Producers
D Decomposers
8 A line graph shows fish population rising from 20 to 50, then dropping sharply to 15. What might have caused this pattern?
A The fish learned to hide better
B A change in the ecosystem like pollution, disease, or a new predator
C The scientist made counting errors
D Fish always decrease in number

Check Your Understanding

Data Tables

Organize information in rows and columns with clear labels and units.

Bar Graphs

Compare different categories using rectangular bars of different heights.

Line Graphs

Show how data changes over time using connected points.

Pie Charts

Show parts of a whole using slices of a circle (percentages).

Trends

Patterns in data: increasing, decreasing, stable, or fluctuating.

Analysis

Looking at data to find patterns and draw conclusions.

Key Takeaways

  • Data tables organize raw numbers; graphs make patterns visible
  • Choose the right graph type based on what you want to show
  • Line graphs are best for showing change over time
  • Always include titles, labels, and units on graphs and tables

Next Steps

  • Create a data table and graph from your own ecosystem observations
  • Practice reading graphs from science magazines or websites
  • Learn how to write scientific explanations using data as evidence
  • Prepare for the unit checkpoint by reviewing all concepts