Worksheet Grade 8 Health & Consumer Science

Bellweather Household Water Bill: A Grade 8 Tiered-Rate Worksheet

A grade 8 consumer-science worksheet where students convert CCF to gallons, compute a tiered water bill, and write the bill as a linear equation.

Grade: Grade 8
Subject: Health & Consumer Science
Material: Worksheet
Time: 40 min
Prep: No prep
Materials: None

Standards

8.F.B.4 Common Core Math

Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description, a table, or a graph, and interpret them in terms of the situation modeled.

How this material aligns: Item 7 asks students to write the monthly bill as a linear function of CCF used, reading the marginal rate as slope and the constant as initial value.

All materials for 8.F.B.4 →

RST.6-8.7 Common Core ELA

Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table).

How this material aligns: Students integrate the written tier rules with the numbers in the sample bill table to compute the total monthly charge.

All materials for RST.6-8.7 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will convert CCF units of water into gallons using the cubic-foot conversion.
Students will compute a tiered monthly water bill from a service charge and two rate tiers.
Students will write and use a linear equation for the monthly bill above the first tier.

Vocabulary

Key words: CCF, tiered rate, service charge, linear equation

Teacher overview

Many water utilities measure use in CCF, which stands for one hundred cubic feet, and charge more per unit as a household uses more. Reading such a bill is a consumer skill that combines a unit conversion with tiered pricing. This worksheet uses a fictional household's bill so students can convert CCF to gallons, work through a two-tier rate structure, and describe the whole bill with a single linear equation.

Bellweather Household Water Bill: A Grade 8 Tiered-Rate Worksheet — Grade 8 Health & Consumer Science

Name: ____________________________ Date: ______________

Student Worksheet

Suppose the Bellweather household, a fictional family in the town of Pennhaven, received the water bill summarized below. One CCF is 100 cubic feet, and one cubic foot holds 7.48 gallons.

Bill line	Amount
Water used this month	7 CCF
Monthly service charge	16 dollars
Tier 1 rate (first 4 CCF)	3 dollars per CCF
Tier 2 rate (each CCF above 4)	5 dollars per CCF

How many gallons are in 1 CCF? Use 100 cubic feet and 7.48 gallons per cubic foot.
How many gallons of water did the Bellweathers use this month, if they used 7 CCF?
Round your gallon answer from item 2 to the nearest hundred, then write it in scientific notation.
What is the Tier 1 charge for the first 4 CCF, at 3 dollars per CCF?
How many CCF fall into Tier 2 this month, and what is the Tier 2 charge at 5 dollars per CCF?
What is the total bill for the month? Add the service charge, the Tier 1 charge, and the Tier 2 charge.
Write a linear equation for the total bill B, in dollars, for a month when the household uses n CCF, assuming n is more than 4. Simplify it to the form B = 5n + a number.
Use your equation from item 7 to predict the bill for a month when the household uses 10 CCF.
A neighbor used only 3 CCF, all inside Tier 1. Find the neighbor's total bill, adding the service charge and the Tier 1 charge for 3 CCF.
Explain how knowing the two tier rates could help a household lower its bill during a dry month.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: 748 gallons.
100 cubic feet times 7.48 gallons per cubic foot equals 748 gallons in 1 CCF.
Answer: 5,236 gallons.
7 CCF times 748 gallons per CCF equals 5,236 gallons.
Answer: 5.2 times ten to the third.
5,236 rounds to 5,200, which is 5.2 times ten to the third power.
Answer: 12 dollars.
The first 4 CCF at 3 dollars each is 4 times 3, or 12 dollars.
Answer: 3 CCF in Tier 2; 15 dollars.
7 CCF minus the first 4 CCF is 3 CCF in Tier 2, and 3 times 5 dollars is 15 dollars.
Answer: 43 dollars.
The 16 dollar service charge plus 12 dollars for Tier 1 plus 15 dollars for Tier 2 equals 43 dollars.
Answer: B = 5n + 8.
The service charge (16) plus the full Tier 1 charge (12) is 28, and Tier 2 adds 5 for each CCF above 4, so B = 28 + 5(n minus 4) = 5n + 8.
Answer: 58 dollars.
B = 5 times 10 plus 8 = 50 + 8 = 58 dollars for 10 CCF.
Answer: 25 dollars.
The 16 dollar service charge plus 3 CCF at 3 dollars each (9 dollars) equals 25 dollars.
Answer: Cutting use keeps CCF out of the higher Tier 2 rate.
Because every CCF above 4 costs 5 dollars instead of 3, trimming outdoor watering to stay near or below 4 CCF avoids the more expensive tier and lowers the bill.

Differentiation

Support

Provide the CCF-to-gallon conversion worked once as a model before item 1, and give a partly filled bill worksheet where the service charge and Tier 1 charge are already entered so students focus on the Tier 2 steps. Allow calculator use throughout.

Extension

Ask students to find the number of CCF at which this household's bill would first pass 60 dollars, using their equation from item 7, and to explain what that usage level means in gallons. Have them check the answer by working the tiers directly.

ELL supports

Pre-teach CCF, service charge, and tier with a labeled sample bill showing each part. Allow items 1 through 6 to be answered by filling numbers into a provided template of steps rather than writing full explanations.