Virginia SOL 8.PFA.3.b
The Standard
Describe key characteristics of linear functions including slope (m), y-intercept (b), and independent and dependent variables.
Virginia Standards of Learning for Mathematics · The student will represent and solve problems, including those in context, by using linear functions and analyzing their key characteristics (the value of the y-intercept (b) and the coordinates of the ordered pairs in graphs will be limited to integers).
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students identify and describe the slope, y-intercept, input, and output of a linear relationship. They connect each feature to equations, graphs, tables, and real situations.
What Mastery Looks Like
- Students correctly identify slope and y-intercept from an equation, graph, table, or context. They explain slope as a rate of change and distinguish the input variable from the output variable.
Common Misconceptions
- Students may confuse slope with the y-intercept or read slope as one coordinate. They may reverse rise and run. They may also label the dependent variable as the input rather than the output.
How to Assess It
- Give students the equation y = -2x + 5 and ask them to identify the slope, y-intercept, independent variable, and dependent variable. Have them explain what the negative slope tells about the graph.
Lesson moves
Ways to Teach It
Use floor tape to make coordinate axes, then have students place points and physically model the rise and run between them.
Ask students to explain how slope and y-intercept describe the situation y = 3x + 10 for a taxi fare.
Play a matching game with cards showing equations, graphs, slopes, y-intercepts, and variable descriptions for several linear functions.
Give a phone plan with a monthly fee and per-gigabyte charge, then identify the starting cost, rate, input, and output.
Free download
Printable 8.PFA.3.b Worksheet
A ready-to-print activity worksheet aligned to 8.PFA.3.b, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- 8.PFA.3.d
Create a table of values for a linear function given a graph, equation in the form of y = mx + b, or context.
- 8.PFA.3.f
Create a context for a linear function given a graph, table, or equation in the form y = mx + b.
- 8.PFA.3.e
Write an equation of a linear function in the form y = mx + b, given a graph, table, or a situation in context.
- 8.PFA.3
The student will represent and solve problems, including those in context, by using linear functions and analyzing their key characteristics (the value of the y...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.