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Lesson plan Grade 4 Math

Quillmont Garden Drip Timers: Minutes, Gallons, and Trips

A grade 4 lesson at a fictional community garden, where students convert hours to minutes, multiply a pump rate by run time, and interpret a leftover trip.

Objectives

  1. Students will express hours in minutes and meters in centimeters for a garden watering plan.
  2. Students will multiply a pump rate by run time to find gallons delivered to a garden bed.
  3. Students will interpret a remainder as one more carrying trip rather than a partial trip.

Vocabulary

Pump
A pump is a machine that adds energy to water to move it or push it uphill, doing the job gravity cannot do on its own. Water systems use many different kinds of pumps to move water from wells, through treatment, and out to customers.

Also: drip line, timer, storage tank, remainder

Teacher overview

The Quillmont Community Garden is a fictional half-acre plot where neighbors grow vegetables in six long raised beds. A small pump lifts water out of a covered storage tank and pushes it through drip lines that release water slowly at the base of each plant, and a timer controls how long each bed is watered. This lesson has students move between the hours written on the garden schedule and the minutes a timer actually accepts, then multiply the pump rate by run time to find gallons. Students frequently write 1 hour 45 minutes as 145 minutes, so the guided practice targets that error directly.

Procedure

Hook (5 min): Lay the 8-meter length of tubing along the classroom floor and ask students to guess how many centimeters long it is. Record three guesses on the board without confirming any of them. Explain that the Quillmont gardeners order tubing in meters but mark planting spots in centimeters, so they convert constantly.

Direct instruction (10 min): Draw the garden on the board as six beds fed by one pump and one tank. Model a conversion students will not repeat on the handout: 3 hours equals 3 × 60 = 180 minutes. Then model the multiplication structure with a rate students will not reuse: a pump moving 7 gallons each minute for 20 minutes delivers 7 × 20 = 140 gallons. Label the rate, the time, and the total on the board so students can name each part.

Guided practice and formative check (12 min): Ask the class to write 1 hour 30 minutes as a number of minutes on scrap paper and hold it up. Look for 90 minutes. If more than five students write 130, stop and rebuild the hour on a number line in six ten-minute hops before continuing. Repeat with 2 hours 20 minutes, looking for 140 minutes.

Independent work (18 min): Distribute the student handout. Students work through all ten questions, showing the multiplication or division for each computation. Circulate and ask two or three students to explain what the leftover gallons in question 10 mean for the volunteer carrying buckets.

Close (5 min): Ask one student to read the answer to question 6 and one to read the answer to question 10. Finish by asking why the garden keeps a tank at all instead of watering straight from a hose, and connect the answer to the storage that every water system needs.

Quillmont Garden Drip Timers: Minutes, Gallons, and Trips — Grade 4 Math
Name: ____________________________ Date: ______________

Student Handout

  1. The garden schedule allows the pump to run up to 2 hours each morning. How many minutes is that?

  2. Each of the 6 beds gets 15 minutes of water. How many minutes of watering is that for all 6 beds?

  3. A gardener sets the timer for 1 hour and 45 minutes. How many minutes is that?

  4. The pump moves 9 gallons of water each minute. How many gallons does it move in 15 minutes?

  5. Use your answer from question 4. How many gallons do all 6 beds get in one morning?

  6. The storage tank holds 1,000 gallons when it is full. Using your answer from question 5, how many gallons are left in the tank after all 6 beds are watered?

  7. The garden is watered on 3 days each week. Using your answer from question 5, how many gallons does the garden use in one week?

  8. Next season the garden will have 9 plots. The club plans to share the 2,430 gallons from question 7 evenly among them. How many gallons would each plot get?

  9. Each drip line is 8 meters long. How many centimeters is that?

  10. A volunteer carries 4 gallons of water per trip. How many trips does it take to carry the leftover gallons from question 6?

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

Answer Key

  1. Answer: 120 minutes.
    One hour is 60 minutes, so 2 hours is 2 × 60 = 120 minutes.

  2. Answer: 90 minutes.
    Six beds at 15 minutes each is 15 × 6 = 90 minutes.

  3. Answer: 105 minutes.
    One hour is 60 minutes, and 60 + 45 = 105 minutes. Students who write 145 have joined the digits instead of converting the hour.

  4. Answer: 135 gallons.
    9 × 15. Splitting 15 into 10 + 5 gives 9 × 10 = 90 and 9 × 5 = 45, and 90 + 45 = 135 gallons.

  5. Answer: 810 gallons.
    135 × 6. Splitting 135 into 100 + 35 gives 100 × 6 = 600 and 35 × 6 = 210, and 600 + 210 = 810 gallons.

  6. Answer: 190 gallons.
    1,000 − 810 = 190 gallons still in the tank after the six beds are watered.

  7. Answer: 2,430 gallons.
    810 × 3. Splitting 810 into 800 + 10 gives 800 × 3 = 2,400 and 10 × 3 = 30, and 2,400 + 30 = 2,430 gallons.

  8. Answer: 270 gallons.
    2,430 ÷ 9. Nine goes into 24 hundreds 2 hundred times, using 1,800 and leaving 630. Nine goes into 630 seventy times with nothing left, so each plot gets 270 gallons.

  9. Answer: 800 centimeters.
    One meter is 100 centimeters, so 8 meters is 8 × 100 = 800 centimeters.

  10. Answer: 48 trips.
    190 ÷ 4 gives 47 with a remainder of 2, because 4 × 47 = 188. The last 2 gallons still need to be carried, so the volunteer makes one more trip for a total of 48.

Differentiation

Support

Give students a labeled conversion strip showing 1 hour as 60 minutes and 1 meter as 100 centimeters, and let them use repeated addition instead of multiplication for questions 2 and 4. For question 10, provide counters grouped in fours so the leftover pair is visible.

Extension

Ask students to redesign the watering plan so that the tank in question 6 finishes the morning with at least 100 gallons left, using the largest whole number of minutes per bed, stating that number and showing the multiplication that proves it.

ELL supports

Pre-teach "drip line," "timer," "tank," and "trip" while pointing to the tubing on the floor and a drawing of the tank feeding six beds. Provide the sentence frame: The pump moves ___ gallons each minute, so in ___ minutes it moves ___ gallons.

Extensions

Have students design a watering schedule for a classroom plant using a measuring cup, record the amount given each day for one week, and total the week in milliliters and then in liters.