📊 Grade 5 Math: Data and Graphs – Notes & Formulae
1. Line Plots
• Interpret Line Plots (Whole Numbers): Identify frequency of each value by counting the markers (X’s) above each number. Useful for quick data comparison.
• Create Line Plots with Decimals/Fractions: Place markers above correct values (including decimal/fraction positions) to represent data counts.
Example: If values are 2, 3, 4, markers above 2, 3, 4 show how many times each occurs.
Line Plot Key Formula: Frequency = Number of X’s above value
2. Line Graphs
• Create Line Graphs: Plot points for each value over categories (often time), then connect with line segments.
• Interpret Line Graphs: Look for trends (increasing, decreasing, steady).
Slope = \(\frac{y_2 - y_1}{x_2 - x_1}\)
3. Bar Graphs
• Create Bar Graphs: Draw bars to represent data categories. Height = frequency.
• Interpret Bar Graphs (Single & Multi-Step): Compare bar heights for answers.
Height_{bar} = Frequency_{category}
4. Frequency Tables
• Create Frequency Tables: List data values and their frequencies.
• Interpret (One-Step & Multi-Step): Add, subtract, compare frequencies for problem-solving.
5. Stem-and-Leaf Plots
• Create Stem-and-Leaf Plots: "Stem" is the leading digits, "Leaf" are trailing digits.
• Interpret Stem-and-Leaf Plots: Quickly see data distribution and calculate median, mode.
6. Scatter Plots
• Create Scatter Plots: Plot (x, y) points; shows relationships/trends.
• Interpret Scatter Plots & Trends: Identify positive, negative, or no correlation. Make predictions by observing patterns.
• Write Two-Variable Equations: Find an equation relating x & y.
- Positive: y\) increases as \(x\) increases
- Negative: y\) decreases as \(x\) increases
- No correlation: No clear pattern
Prediction Formula: Estimate future value by extrapolating the line of best fit.
Quick Data Display Comparison (Summary Table)
| Type | Best For | Key Feature |
|---|---|---|
| Line Plot | Small data sets | Shows frequency of values |
| Bar Graph | Categorical data | Compares categories |
| Line Graph | Time series | Shows trends |
| Stem-and-Leaf | Data distribution | Keeps all actual values |
| Frequency Table | Tally counts | Summarizes data |
| Scatter Plot | Relationships | Shows patterns/correlation |