Grade 10 Lesson plan
Farrowdean Combined Sewer: Storm Storage as a Constraint
A 55-minute grade 10 lesson in which students model a fictional town's storm storage tank as an inequality in rate and duration, then judge four storms as viable or not.
Common Core Math · High School
HSA-CED.A.2 Create equations in two or more variables
Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.
Why water teaches this standard well
Students write and graph an equation relating gallons remaining in a tank to elapsed time, labeling and scaling the axes to match the tank's real capacity and fill schedule. Properly labeled, scaled axes here turn an abstract equation into a chart a plant operator could actually read.
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.
41 materials aligned to HSA-CED.A.2
Lesson plans
Grade 11 Lesson plan
Keldwick's Ivelbrook Avenue Main: A Log-Log Fit for Head Loss
A 55-minute grade 11 lesson where students test proportionality, take logarithms of flow and head-loss data, and recover a power model for an aging transmission main.
Grade 9 Lesson plan
Garrowby Water Authority: Two Entry Paths as a System of Equations
A 55-minute grade 9 lesson where students model cumulative earnings for two routes into a water utility and solve the system for the year the totals meet.
Grade 9 Lesson plan
Thrushmere Well Field Permit: Pumping Limits as Inequalities
A 50-minute grade 9 lesson where students write a system of inequalities for two wells' permit caps and test proposed pumping plans for viability.
Grade 9 Lesson plan
The Marwick Household Water Audit: A Grade 9 Home-Use Model Lesson
Students build and graph an equation for a fictional family's daily water use, then test which single change saves the most water at home.
Grade 9 Lesson plan
Reading the Prewitt Family's Tiered Water Bill in Dunbar
A grade 9 consumer-science lesson where students model a fictional tiered water bill as equations and test it against an affordability threshold.
Grade 10 Lesson plan
Fennmoor Lead Service Line Replacement: A Linear Model Lesson
A 50-minute grade 10 lesson where students build a linear function for a fictional city's lead service line replacement and check it against the 10-year federal deadline.
Grade 10 Lesson plan
Wrenhaven Tiered Water Rates: Writing and Solving Bill Equations
A 50-minute grade 10 lesson where students model a fictional town's tiered water rates as equations, compute monthly bills, and solve for usage at a target bill.
Grade 12 Lesson plan
Vernbrook Reservoir: A Dry-Summer Water Budget Model
A 50-minute grade 12 lesson where students track a fictional reservoir's monthly storage with a water-budget equation and model its decline.
Grade 9 Lesson plan
Ostgard Tiered Water Rates: A Block-Pricing Equations Lesson
A 55-minute grade 9 lesson where students write and graph a tiered water-rate equation for the Ostgard utility and test bills against an affordability threshold.
Grade 12 Lesson plan
Marlowe Ferry's Main Replacement: Rate Surcharge or Revenue Bond
A grade 12 lesson where students compute and compare a pay-as-you-go rate surcharge and a revenue-bond surcharge to fund a fictional utility's capital program.
Grade 10 Lesson plan
Amberlin Water District: Comparing Two Billing Plans by Equation
A grade 10 lesson where students solve and graph a system of linear equations to find the break-even usage point between two fictional water utility billing plans.
Worksheets
Grade 10 Worksheet
Cinderhill Wellfield Capacity: A Grade 10 Drawdown Worksheet
A grade 10 engineering worksheet on groundwater supply: students find well drawdown and specific capacity, combine well yields, and model yield as a function of drawdown.
Grade 9 Worksheet
Hollisford Well Field: Specific Capacity and Drawdown Worksheet
A grade 9 worksheet on well drawdown and specific capacity, where students build and solve a linear model for a fictional municipal well.
Grade 9 Worksheet
Marlbrook Lead Service Lines: A Replacement-Schedule Worksheet
A grade 9 worksheet where students model Marlbrook's 10-year lead service line replacement with a linear equation and check homes against the lead action level.
Grade 9 Worksheet
Marren River Oxygen Log: A Dissolved Oxygen Data Worksheet
A grade 9 worksheet using a fictional river's dissolved oxygen readings to find average rate of change and build a linear model against the 5 mg/L fish threshold.
Grade 9 Worksheet
Wrayford Beck Watershed: Rain Depth to Reservoir Yield
A grade 9 worksheet on a fictional watershed where students write a runoff equation and convert an annual yield to gallons, MGD, and cubic feet per second.
Grade 10 Worksheet
Pellworth Booster Pump Station: Run-Time and Energy Worksheet
A grade 10 engineering worksheet sizing a fictional booster pump's daily run-time, pipe velocity, and energy use, and writing a gallons-versus-time equation.
Grade 9 Worksheet
Setting Bridgeton's Water Rates: Tiered Pricing and Affordability
Grade 9 worksheet where students build a two-variable equation for a fictional town's tiered water rate, then test the bill against a real affordability threshold.
Math problem sets
Grade 12 Math problem set
Halbrook Water: Uniform Versus Inclining Block Rate Break-Evens
A grade 12 set comparing a uniform water rate with a three-block piecewise rate: two break-evens, interval answers, and a year of seasonal bills.
Grade 11 Math problem set
Danecross Dam Generation: A Hydro Operator Problem Set
A grade 11 careers problem set in which students take a hydro operator's shift, computing station output from flow and head and writing output as a function of flow.
Grade 11 Math problem set
Calderwick Water Rates: A Two-Part Bill and Rate-Increase Problem Set
A grade 11 engineering problem set on a utility's two-part water rate: writing bill equations, comparing a rate increase, and testing an affordability threshold.
Grade 10 Math problem set
Nyefield Blending Plan: A Two-Source System of Equations
A grade 10 problem set where students solve a two-variable system to blend purified recycled water with hard groundwater for a fictional district in drought.
Grade 11 Math problem set
Ansel Gorge Reservoir: Drawdown Functions and Storage Equations
A grade 11 problem set modeling a fictional reservoir's drought drawdown and refill with linear functions, graph features, and a two-variable storage equation.
Grade 11 Math problem set
Seabright Bay Desalination: Reverse-Osmosis Recovery and Energy
A grade 11 problem set on a fictional seawater RO plant, finding permeate and brine flows, percent recovery and salt rejection, an equation model, and daily energy cost.
Grade 12 Math problem set
Fallowfield Water Utility: Revenue and an Inclining Block Rate
A grade 12 problem set on utility finance, covering a fictional utility's revenue need with a fixed charge and a three-tier inclining block rate.
Grade 9 Math problem set
Ferncliff Dam: Reservoir Flow and Hydropower Energy
A grade 9 problem set at the fictional Ferncliff Dam, using Q equals A times V for penstock flow, converting cfs to gpm and MGD, and separating power from energy.
Grade 9 Math problem set
Hartwell Water Rates: Funding a Pipe Replacement Plan
A grade 9 problem set where students model a fictional town's water bill, calculate a rate increase and affordability burden, and graph a pipe-replacement schedule.
Grade 9 Math problem set
Oakmere Pump Station: Wet Well Flow and Run Time
A grade 9 problem set at the fictional Oakmere pump station, finding wet-well volume, using Q equals A times V, converting cfs and MGD, and modeling the emptying time.
Grade 9 Math problem set
Pinebluff Water Rates: Tiered Billing and Break-Even
A grade 9 problem set on the fictional Pinebluff utility, building a tiered water bill as a linear equation and solving for where two rate plans cost the same.
Grade 9 Math problem set
Verwood Irrigation District: A Crop Water Budget Problem Set
A grade 9 problem set converting inches of applied water into acre-feet, gallons, and MGD to size a fictional irrigation district's seasonal water budget.
Grade 9 Math problem set
Pinch Creek Reservoir: Graphing Two Drought Conservation Paths
A grade 9 math problem set where students build and graph linear equations for a fictional reservoir's storage under current withdrawal versus a conservation order.
Projects
Grade 9 Project
Thurlby's Stormwater Fee: Setting a Rate and a Credit Schedule
A five-session grade 9 project where teams measure hard surfaces, build a revenue equation for a town stormwater fee, and defend a credit schedule to a council panel.
Grade 10 Project
Ostlin's Drought Plan: A Spreadsheet Water Budget
A five-session grade 10 project where teams build a monthly spreadsheet water budget for a growing town, stress-test it, and choose a 15-year drought plan.
Grade 11 Project
Thessley Growers Co-op: A Season Irrigation Service Plan
A grade 11 careers project in which teams build a season preventive maintenance calendar, crew-hour budget, and cost model for a fictional irrigation cooperative.
Grade 11 Project
Varnwell's Pumping Schedule: Least Cost Under a Time-of-Use Tariff
A four-session grade 11 project where teams build an hourly tank balance, design a 24-hour pumping schedule under storage limits, and defend its cost to a board panel.
Grade 11 Project
Amberly Landing's Drought Plan for Corvie Reservoir
A five-session grade 11 project building a monthly reservoir balance for a fictional district, then designing drought stages that hold a protected level.
Grade 9 Project
Marrowfield's Water Loss: A Non-Revenue Water Reduction Project
A grade 9 project where teams audit a fictional utility's water loss, model savings with linear equations, and propose a repair plan within a fixed budget.
Grade 9 Project
Sundale Reservoir Supply and Demand: A 20-Year Modeling Project
A multi-session grade 9 project where teams model Sundale's reservoir supply and city demand over 20 years, then propose a conservation plan to close the gap.
Grade 10 Project
Sundown Bay Water Budget: Conservation and Desalination Project
A 4-session grade 10 project where teams use a system of inequalities to design a feasible conservation-and-desalination plan within a fictional town's budget.
Grade 9 Project
Aldergate's Aging Pipes: A Water-Main Break Trend and Budget Project
A grade 9 project where students model a fictional town's rising water-main break trend and propose a pipe-replacement plan within budget and construction limits.