Common Core Math · Grade 8
Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line and assess the model fit by judging the closeness of the data points to the line.
Why water teaches this standard well
Students sketch a best-fit line through several years of streamflow data plotted against time to estimate whether flow is trending up or down, then judge by eye how closely the points hug the line. Informally fitting a trend line to streamflow data previews the formal regression work of high school statistics.
Materials tagged with this code are written to the full standard , and each carries a written note explaining the alignment. See how we review materials.
Grade 8 Lesson plan
A 55-minute grade 8 lesson where students scatter-plot a fictional creek's dissolved oxygen against temperature, describe the association, and fit a trend line by eye.
Grade 8 Worksheet
A grade 8 worksheet where students plot pipe age against main breaks for a fictional district, use a given line of fit to predict, and judge how well the line fits.
Grade 8 Worksheet
A grade 8 worksheet in which students plot pipe age against water main breaks for ten neighborhoods, find the outlier, and weigh two pipe replacement strategies.
Grade 8 Worksheet
A grade 8 worksheet where students plot chloride against conductivity for a salted river, draw a line of best fit, and use its slope to predict values.
Grade 8 Worksheet
A grade 8 worksheet in which students plot ten weeks of rainfall and pumping records from a fictional orchard, use a given line of fit, and read its slope.
Grade 8 Math problem set
A grade 8 science problem set where students scatter-plot creek temperature and dissolved oxygen, fit a trend line, and predict when oxygen drops below the fish limit.
Grade 8 Math problem set
A grade 8 problem set where students scatter-plot eight years of rainfall and reservoir inflow data, fit a trend line by eye, and set a spillway capacity constraint.
Grade 8 Math problem set
A grade 8 math problem set where students scatter-plot a fictional reservoir's rainfall and storage data, use a given fitted line, and evaluate its predictions.
Grade 8 Lab / experiment
Students time a bead task before and after short cool-water hand soaks, plot class data, and explain why cold water below a dam is risky for swimmers.
Grade 8 Lab / experiment
A grade 8 engineering lab where students test how lift height affects a hand pump's flow rate, then graph the results on a scatter plot and fit a trend line.
Grade 8 Classroom activity
A grade 8 activity where groups scatter-plot household size against weekly water use, describe the association, and fit a line to predict a larger household's use.
Grade 8 Classroom activity
A grade 8 activity in which students stand on a taped floor grid to build a class scatter plot of rainfall and turbidity from a fictional creek's sample cards.
Grade 8 Project
A five-session grade 8 project where teams plot twenty fictional storms, fit a line by eye, and report a rain and turbidity finding to a local board.
Grade 8 Quiz & test questions
A grade 8 unit test on a fictional water utility covering linear functions, slope, solving equations, and fitting a line to scatter plot data.