Math problem set Grade 4 Math

Hadley Water Bills: Money, Gallons, and Rounding

A grade 4 problem set: students work out fictional Hadley water bills from a flat fee and a charge per 1,000 gallons, then round the yearly totals.

Grade: Grade 4
Subject: Math
Material: Math problem set
Time: 35 min
Prep: No prep
Materials: None

Standards

4.MD.A.2 Common Core Math

Use the four operations to solve word problems involving distances, intervals of time, liquid volumes, masses of objects, and money, including problems involving simple fractions or decimals, and problems that require expressing measurements given in a larger unit in terms of a smaller unit.

How this material aligns: Problems 1 through 4 and 8 combine a flat dollar fee with a per-gallon charge to find a total bill, the money-and-measurement word problems this standard names.

All materials for 4.MD.A.2 →

4.NBT.A.3 Common Core Math

Use place value understanding to round multi-digit whole numbers to any place.

How this material aligns: Problems 5 and 9 ask students to round three-digit yearly bill totals to the nearest ten and the nearest hundred dollars using place value, the multi-digit rounding this standard names.

All materials for 4.NBT.A.3 →

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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 find a total water bill by combining a flat fee with a per-gallon charge.
Students will round a yearly bill total to the nearest ten or hundred dollars.

Vocabulary

Key words: flat fee, bill, round

Teacher overview

In the fictional town of Hadley, every home pays a monthly water bill made of two parts: a flat fee that is the same for everyone, plus a charge for the water actually used. This set has students build each bill by multiplying and adding, then round some totals, joining the money word problems of 4.MD.A.2 with the rounding of 4.NBT.A.3. Each problem states its own numbers. A common error is to forget the flat fee and report only the water charge, so remind students that both parts belong in the total.

Hadley Water Bills: Money, Gallons, and Rounding — Grade 4 Math

Name: ____________________________ Date: ______________

Problems

The town of Hadley sends a water bill each month. Every home pays a flat fee of $6. Then it pays $3 for each 1,000 gallons of water used. Use these rules for each problem.

The Ruiz home used 4,000 gallons. What is the water charge, not counting the flat fee?
Add the $6 flat fee to your answer from problem 1. What is the full bill?
The Amin home used 7,000 gallons. What is its full bill?
The Boone home used 2,000 gallons. What is its full bill?
The Amin home pays that same bill every month. Its bills for the year add up to $324. Round $324 to the nearest ten dollars.
The Ruiz home used 4,000 gallons in June and 5,000 gallons in July. How many gallons is that in all?
A home's water charge was $15. How many thousands of gallons did it use?
Two homes each have a full bill of $18. How much do they pay together?
The Cole home's full bill is $33 every month, so its bills for the year add up to $396. Round $396 to the nearest ten dollars and to the nearest hundred dollars.

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: $12. The charge is $3 for each 1,000 gallons, and 4,000 gallons is 4 thousands, so 4 × $3 = $12.
Answer: $18. Add the flat fee: $12 + $6 = $18.
Answer: $27. 7 thousands × $3 = $21 for water, plus the $6 fee, so $21 + $6 = $27.
Answer: $12. 2 thousands × $3 = $6 for water, plus the $6 fee, so $6 + $6 = $12.
Answer: $320. $324 is between $320 and $330. The ones digit is 4, which is less than 5, so it rounds down to $320.
Answer: 9,000 gallons. 4,000 + 5,000 = 9,000 gallons.
Answer: 5 thousands (5,000 gallons). Each 1,000 gallons costs $3, and $15 ÷ $3 = 5, so the home used 5,000 gallons.
Answer: $36. Two bills of $18 each: $18 + $18 = $36.
Answer: $400 to the nearest ten and $400 to the nearest hundred. $396 is between $390 and $400, and the ones digit 6 is 5 or more, so it rounds up to $400. $396 is also between $300 and $400, and the tens digit 9 is 5 or more, so it rounds up to $400.

Differentiation

Support

Give students a two-box organizer labeled "water charge" and "flat fee" so they can find each part before adding. Provide a chart that lists the water charge for 1,000 through 9,000 gallons already worked out, so students who are still learning multiplication can focus on adding the fee and rounding.

Extension

Ask students to find the full bill for a home that used 10,000 gallons, then explain in writing which part of the bill grows when a home uses more water and which part stays the same.

ELL supports

Pre-teach "flat fee" and "charge" with a simple picture of a bill split into two boxes. Provide a sentence frame: "The full bill is the water charge plus the flat fee, so the total is ___."