Math problem set Grade 4 Math

Granite Falls Treatment Plant: Pumping, Dividing, and Rounding Gallons

A grade 4 math set where students multiply a pump's flow rate by minutes and days, divide totals among tanks, and round results for a fictional plant's report.

Grade: Grade 4
Subject: Math
Material: Math problem set
Time: 40 min
Prep: No prep
Materials: Calculator (optional)

Standards

4.NBT.B.5 Common Core Math

Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

How this material aligns: Problems 1, 2, and 5 require multiplying two two-digit numbers (a flow rate by minutes) and multiplying a four-digit daily total by a one-digit number of days, exactly the two multiplication forms this standard names.

All materials for 4.NBT.B.5 →

4.NBT.B.6 Common Core Math

Find whole-number quotients and remainders with up to four-digit dividends and one-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

How this material aligns: Problem 7 divides a four-digit total by a one-digit number of storage tanks and asks students to find any remainder, the division and remainder skill this standard targets. Problem 3 uses the same method on a five-digit total, so it goes past this standard's four-digit limit and works as a stretch item.

All materials for 4.NBT.B.6 →

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 4 and 8 round the plant's pumped totals to the nearest thousand and nearest hundred for a summary report, the place-value rounding skill this standard covers.

All materials for 4.NBT.A.3 →

Download Word file

This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-16.

Objectives

Students will multiply two two-digit numbers and a four-digit number by a one-digit number to find total gallons pumped.
Students will divide a multi-digit total by a one-digit number of tanks and interpret any remainder.
Students will round multi-digit totals to a given place value for a summary report.

Vocabulary

Flow rate: Flow rate measures how much water moves past a point in a certain amount of time, like gallons per minute through a garden hose. Bigger pipes and stronger pushes give bigger flow rates.
Clearwell: A clearwell is a large storage tank at a treatment plant that holds finished water right after it comes out of the filters. It gives the disinfectant enough time to work before the water is pumped out to homes and businesses.

Also: remainder, round

Teacher overview

At the fictional Granite Falls Water Treatment Plant, a pump moves treated water into storage tanks before it is sent out to homes. This problem set follows one pump through a week's schedule: finding how many gallons it moves each morning, adding up a week's total, splitting that total evenly among the plant's storage tanks, and rounding totals for the plant's weekly report. A common misconception in this kind of problem is mixing up which number represents "the amount each tank gets" and which represents "the amount left over," especially when the leftover amount does not get its own tank.

Granite Falls Treatment Plant: Pumping, Dividing, and Rounding Gallons — Grade 4 Math

Name: ____________________________ Date: ______________

Problems

The plant's main pump moves 85 gallons of water each minute. It runs for 45 minutes each morning. How many gallons does it move in one morning?
The pump runs this same cycle every morning for 6 days. Use your answer to problem 1. What is the total for the 6 days?
The operator splits the week's total from problem 2 evenly among 4 tanks. How many gallons go into each tank? How many gallons are left over?
Round the week's total from problem 2 to the nearest thousand gallons.
A second pump moves 68 gallons each minute. It runs for 42 minutes on one day. How many gallons does it move?
That same day, both pumps run their normal schedules (problems 1 and 5). What is the total for both pumps that day?
The operator splits the day's total from problem 6 evenly among 3 tanks. How many gallons go into each tank? How many gallons are left over?
Round the day's total from problem 6 to the nearest hundred gallons.

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: 3,825 gallons.
85 gallons/minute × 45 minutes = 85 × 45. Splitting 45 into 40 + 5: 85 × 40 = 3,400, and 85 × 5 = 425. 3,400 + 425 = 3,825 gallons.
Answer: 22,950 gallons.
3,825 gallons/day × 6 days = 22,950 gallons. Splitting 3,825 into 3,800 + 25: 3,800 × 6 = 22,800, and 25 × 6 = 150. 22,800 + 150 = 22,950 gallons.
Answer: 5,737 gallons per tank, 2 gallons left over.
22,950 ÷ 4: 4 × 5,000 = 20,000, leaving 2,950. 4 × 700 = 2,800, leaving 150. 4 × 37 = 148, leaving 2. Adding the partial quotients: 5,000 + 700 + 37 = 5,737, with a remainder of 2 gallons that stay in the plant's clearwell until the next pumping cycle.
Answer: 23,000 gallons.
22,950 is 950 above 22,000 and only 50 below 23,000, so it rounds up to 23,000 gallons.
Answer: 2,856 gallons.
68 gallons/minute × 42 minutes = 68 × 42. Splitting 42 into 40 + 2: 68 × 40 = 2,720, and 68 × 2 = 136. 2,720 + 136 = 2,856 gallons.
Answer: 6,681 gallons.
Problem 1's total (3,825 gallons) plus problem 5's total (2,856 gallons): 3,825 + 2,856 = 6,681 gallons.
Answer: 2,227 gallons per tank, no gallons left over.
6,681 ÷ 3: 3 × 2,000 = 6,000, leaving 681. 3 × 200 = 600, leaving 81. 3 × 27 = 81, leaving 0. Adding the partial quotients: 2,000 + 200 + 27 = 2,227, with no remainder, since the total divides evenly among the 3 tanks.
Answer: 6,700 gallons.
6,681 is 81 above 6,600 and only 19 below 6,700, so it rounds up to 6,700 gallons.

Differentiation

Support (below grade level)

Break problems 1, 2, 5, and 6 into two smaller boxes on the handout, one for each partial product or addend, so students only need to add the pieces together rather than track the whole multiplication in one step. Allow a calculator to check division answers after students show the multiplication step by hand. Problem 3 divides a five-digit number, one place past the grade 4 standard, so treat it as optional for students who need support.

Extension (above grade level)

Ask students to design a third pump with its own flow rate and daily run time so that the three-pump combined weekly total rounds to exactly 30,000 gallons, and to show the calculations that prove their design works.

ELL supports

Pre-teach "flow rate," "clearwell," and "remainder" using a labeled diagram of a pump filling a tank, with an arrow showing gallons flowing in each minute. Provide a sentence frame: "The pump moves ___ gallons because it runs at ___ gallons per minute for ___ minutes."