Worksheet Grade 6 Math

Ottershaw's Hydrant Flushing Log: Decimals and Unit Rates

A grade 6 worksheet on a spring hydrant flushing route, where students divide decimals to find gallons per minute and compare four hydrants' rates.

Grade: Grade 6
Subject: Math
Material: Worksheet
Time: 35 min
Prep: No prep
Materials: None

Standards

6.RP.A.2 Common Core Math

Understand the concept of a unit rate a/b associated with a ratio a:b with b not equal to 0, and use rate language in the context of a ratio relationship.

How this material aligns: Items 1 through 4 ask students to name each hydrant's gallons-per-minute rate, which is the per-one rate language this standard defines.

All materials for 6.RP.A.2 →

6.NS.B.3 Common Core Math

Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.

How this material aligns: Item 8 adds the decimal minute readings, and items 3, 9, and 12 divide by or multiply by a decimal, using the standard algorithms this standard names.

All materials for 6.NS.B.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 divide gallons by minutes to find a unit rate in gallons per minute.
Students will add and divide decimal quantities from a flushing log.
Students will find what percent one hydrant's use is of a route total.

Vocabulary

Key words: unit rate, hydrant, flushing, decimal

Teacher overview

The town of Ottershaw opens its fire hydrants every spring to push sediment out of the water mains before summer. A two-person crew records how long each hydrant runs and how many gallons it uses, and that log is the whole data set for this worksheet. Students divide gallons by minutes to find each hydrant's rate, then compare rates and shares of the route total. The error to watch for is dividing minutes by gallons instead of gallons by minutes, which returns a number close to zero; students who report a rate under 1 have usually reversed the divisor and the dividend.

Ottershaw's Hydrant Flushing Log: Decimals and Unit Rates — Grade 6 Math

Name: ____________________________ Date: ______________

Student Worksheet

The town of Ottershaw flushed four hydrants on Tuesday morning. The crew's log is below. Use it for every item on this page.

Hydrant	Minutes open	Gallons used
H-1	6.0	1,020
H-2	4.0	700
H-3	7.5	1,200
H-4	6.0	1,080

H-1 ran 6.0 minutes and used 1,020 gallons. Find its rate in gallons per minute. Show the division.
H-2 ran 4.0 minutes and used 700 gallons. Find its rate in gallons per minute.
H-3 ran 7.5 minutes and used 1,200 gallons. Find its rate in gallons per minute.
H-4 ran 6.0 minutes and used 1,080 gallons. Find its rate in gallons per minute.
Which hydrant had the greatest rate in gallons per minute?
How much greater is that hydrant's rate than the rate of H-3?
How many gallons did the four hydrants use in all?
How many minutes were the four hydrants open in all?
Divide your total gallons from item 7 by your total minutes from item 8. Round to the nearest tenth. This is the crew's rate for the whole route.
What percent of the route's total gallons did H-3 use?
The crew planned to use no more than 4,500 gallons on this route. What percent of that plan did the crew actually use? Round to the nearest whole percent.
A fifth hydrant, H-5, ran 5.5 minutes at a rate of 160 gallons per minute. How many gallons did it use?
H-3 used more gallons than any other hydrant, yet it had the lowest rate in gallons per minute. Explain how both of those statements can be true.

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: 170 gallons per minute.
1,020 gallons divided by 6.0 minutes equals 170 gallons per minute.
Answer: 175 gallons per minute.
700 gallons divided by 4.0 minutes equals 175 gallons per minute.
Answer: 160 gallons per minute.
1,200 gallons divided by 7.5 minutes equals 160 gallons per minute.
Answer: 180 gallons per minute.
1,080 gallons divided by 6.0 minutes equals 180 gallons per minute.
Answer: Hydrant H-4.
Its rate of 180 gallons per minute is greater than 170, 175, and 160.
Answer: 20 gallons per minute.
180 minus 160 equals 20 gallons per minute.
Answer: 4,000 gallons.
1,020 plus 700 plus 1,200 plus 1,080 equals 4,000 gallons.
Answer: 23.5 minutes.
6.0 plus 4.0 plus 7.5 plus 6.0 equals 23.5 minutes.
Answer: 170.2 gallons per minute.
4,000 divided by 23.5 equals 170.212..., which rounds to 170.2. Accept 170.2 or a clearly labeled answer of about 170 gallons per minute.
Answer: 30 percent.
1,200 divided by 4,000 equals 0.30, which is 30 percent.
Answer: 89 percent.
4,000 divided by 4,500 equals 0.888..., which rounds to 89 percent.
Answer: 880 gallons.
160 gallons per minute times 5.5 minutes equals 880 gallons.
Answer: Gallons used depends on the rate and on the time together.
H-3 ran 7.5 minutes, longer than any other hydrant, so a slower rate still added up to the largest total. A hydrant with a fast rate and a short run can use fewer gallons than a slow hydrant left open longer.

Differentiation

Support

Give students a worked model for H-1 with the division set up as gallons over minutes, and label the parts as "gallons" and "minutes" so the order is visible. Allow a calculator for items 9 and 11, and provide a percent double number line with 0, 50, and 100 already marked for item 10.

Extension

Ask students to plan a fifth route stop so that the crew's route rate from item 9 rises to exactly 175 gallons per minute. They must state the new hydrant's minutes and gallons and show the division that proves the new route rate.

ELL supports

Pre-teach "flush," "hydrant," "rate," and "per" with a labeled sketch of a hydrant with an arrow showing water leaving. Provide the sentence frame "Hydrant ___ used ___ gallons in ___ minutes, so its rate is ___ gallons per minute" for items 1 through 4, and allow item 13 to be answered with two sentences using that frame.

Extensions

Have students collect the time and volume for one real classroom or home task, such as filling a bucket from a hose, and compute its rate in gallons per minute. Comparing that household rate with the hydrant rates on this page makes the size of a flushing flow concrete.