8.F.5: Describe qualitatively the functional relationship between two quantities by analyzing a graph (e.g., where the function is increasing or decreasing, linear or nonlinear). Sketch a graph that exhibits the qualitative features of a function that has been described verbally.
I can describe the relationship between two quantities by looking closely at a graph. I can sketch a graph that shows the features of a unction that has been described aloud.
What Your Child Needs to Know
Understanding the relationship between two quantities and how they are represented on a graph is a crucial skill in eighth-grade mathematics. This ability allows students to interpret and analyze real-world situations mathematically. By learning to describe and sketch graphs based on verbal descriptions, students develop a deeper comprehension of functions and their practical applications. Mastery of these skills is not only fundamental for advanced mathematics but also essential in various real-world contexts such as science, economics, and technology, where data interpretation is key.
Real World Practice
Visual models and hands-on activitiesHands-on Activities
1. Graph the Weather
Track the daily high temperatures for a week and plot them on a graph. Discuss whether the temperature trend is increasing or decreasing and predict the next day's temperature based on the graph.
2. Budget Balancing
Create a graph based on a weekly allowance and spending. Identify periods where spending is faster than saving and discuss ways to balance or improve the budget.
3. Walk and Graph
Measure and record the time it takes to walk specific distances. Graph these times against the distances and analyze the shape of the graph to determine if the relationship is linear or nonlinear.
4. Science Experiment Observations
Conduct a simple science experiment, such as observing plant growth under different light conditions. Graph the growth over time and describe the relationship between light exposure and growth rate.
5. Classroom Polls
Conduct a poll in class about favorite books or sports and graph the results. Discuss how the graph's shape changes with different types of questions and answer choices.
Quick Checks
Strategies and quick activitiesStrategies When Your Child Struggles
1. Graph Reading Nightly
Encourage your child to describe graphs from newspapers or magazines each night to build familiarity and comfort with different types of graphs.
2. Use Manipulatives
Use physical objects like coins or blocks to create a visual representation of quantities and their changes, helping to conceptualize the graphing of these quantities.
3. Drawing Descriptions
Have your child listen to a verbal description of a scenario and then draw a graph to represent it, helping them visualize verbal information.
4. Graph Vocabulary Flashcards
Create flashcards with key vocabulary such as 'increasing', 'decreasing', 'linear', 'nonlinear', and use them regularly to reinforce understanding.
5-Minute Activities
Activity 1: Graph Sketch Relay
Give a verbal description of a function, and have your child quickly sketch a graph to match. Time them and make it a fun challenge.
Activity 2: Daily Graph Insights
Ask your child to describe one graph a day from different media sources, focusing on the type of relationship shown.
Activity 3: Function Story Game
Make up stories or situations and ask your child to sketch a graph that could represent that situation.
Activity 4: Graph Matching Game
Create cards with graphs and separate cards with descriptions of the graphs. Mix them up and have your child match each graph to its correct description.
Check Progress
Track improvementMid-Year Expectations
By the middle of 8th grade, your child should be able to:
- Students should be able to identify whether a graph shows an increasing or decreasing trend.
- Students should begin to differentiate between linear and nonlinear relationships in simple graphs.
End-of-Year Expectations
By the end of 8th grade, your child should be able to:
- Students should be capable of sketching a graph from a verbal description of a relationship between two quantities.
- Students should confidently analyze complex graphs and describe the type of relationship they represent.
Mastery Signs
Your child has mastered this standard when they can:
- Can accurately sketch and interpret both linear and nonlinear graphs.
- Can verbally describe the features of a graph without seeing it, based on a description of the function.
Questions to Ask:
Ask your child to solve these problems and explain their process:
- Describe the relationship shown in the graph of a car’s speed over time.
- Sketch a graph that would represent a balloon’s height above the ground after it is released.
- Identify whether the graph of temperature versus time of day is linear or nonlinear, and explain why.
- Given a story about a runner’s speed during a race, draw a graph that could represent their speed over time.