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Lab / experiment Grade 5 Science

Three Soils at Pelmore Flats: A Grade 5 Soak-Through Fair Test

Students time the same cup of water through sand, garden soil, and a half-and-half mix to recommend a soil for a fictional town's rain garden and name what to improve.

Objectives

  1. Students will run a fair test by changing only the soil while holding the water amount constant.
  2. Students will record and compare how long water takes to pass through three soils.
  3. Students will recommend a soil for a rain garden and name one change worth testing next.

Vocabulary

Rain garden
A rain garden is a shallow planted dip in the ground that catches rain running off a roof or driveway and lets it soak slowly into the soil. Its deep-rooted plants help clean the water.

Also: soak in, fair test, variable, runoff

Teacher overview

The fictional town of Pelmore Flats wants to build a rain garden in the low corner of its ballfield, and the parks crew has to choose what soil to fill it with. This investigation asks which of three soils lets water soak in fastest, and it answers that question with a fair test in which the water amount, the column size, and the pour are all held steady while only the soil changes. Teams also watch for water that stays pooled on the surface for a long time, which tells the crew a soil drains too slowly and would overflow instead of soaking rain in. The results support a real recommendation, and the last analysis question turns the finding into a labeled model of where rain goes on a yard and on pavement.

Three Soils at Pelmore Flats: A Grade 5 Soak-Through Fair Test — Grade 5 Science
Name: ____________________________ Date: ______________

Procedure

Step 1. Put on safety goggles. Do not taste anything in this lab. The teacher has already cut the bottoms off the bottles, so do not use scissors or a knife on them.

Step 2. Turn each bottle upside down so the neck points down. Put a coffee filter over the mouth of each bottle and hold it there with a rubber band.

Step 3. Label the three bottles Sand, Soil, and Mix. Stand each one neck down in its own collection jar. Set all three jars on the tray.

Step 4. Pour 2 cups of dry play sand into the bottle labeled Sand. Pour 2 cups of dry garden soil into the bottle labeled Soil. Pour 2 cups of the half-and-half mix into the bottle labeled Mix. Tap each bottle once on the table so the material settles the same way.

Step 5. Look at all three columns before adding water. Write down what each one looks like on the top surface.

Step 6. Fill the measuring cup with exactly 1 cup of water. You will use 1 cup for every column, because keeping the water the same is what makes this a fair test.

Step 7. Have one team member start the stopwatch at the same moment another member begins pouring the 1 cup of water into the Sand column. Pour steadily and from a low height, close to the surface.

Step 8. Stop the watch when water stops dripping into the jar for a full 10 seconds. Write that time in the table.

Step 9. Write down whether any water sat on top of the column before it soaked in, and about how long it sat there.

Step 10. Repeat steps 6 through 9 for the Soil column, then again for the Mix column. Use 1 cup of water each time and pour from the same low height each time.

Step 11. Look at the water in the three jars. Write down which one looks cloudiest.

Step 12. Pour the water down the drain. Put the used sand, soil, and mix in the trash or in a garden bed. Wipe the tray, and wash your hands.

Data & Analysis

Fill in the table as you work.

Column Time for the water to finish dripping Did water sit on top first, and for how long How cloudy the collected water looks
Sand
Soil
Mix
  1. Which column finished dripping first? Give the time from your table.
  2. Which column took the longest? Give its time, and say how much longer it took than the fastest one.
  3. You poured exactly 1 cup of water into every column. Explain why using the same amount each time matters in this test.
  4. Name one thing your team kept the same on purpose and one thing your team changed on purpose.
  5. Water sat on top of at least one column before it soaked in. What does that tell the Pelmore Flats crew about using that soil in a rain garden, and what one change would you test next?
  6. Draw a labeled side view with rain falling on a grassy yard on one side and on a paved parking lot on the other. Use arrows to show where the water goes in each place. Then write one sentence naming the two Earth systems your arrows connect.

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: Usually the Sand column. Accept whichever column the team's own table shows as fastest, as long as the time is copied correctly. Sand grains are large with wide spaces between them, so water moves through in well under a minute in most classrooms.
  2. Answer: Usually the Soil column. Accept the team's own slowest column and its time, and check that the difference is a correct subtraction of the two recorded times. Garden soil holds fine particles that pack together and slow the water.
  3. Answer: Using the same amount keeps the test fair. If one column got more water, a longer time might come from the extra water instead of from the soil, so nobody could tell which cause produced the result.
  4. Answer: Kept the same: the 1 cup of water, the size of the bottle, the 2 cups of material, the pour height, and the way the column was tapped. Changed on purpose: only the kind of material in the column. Accept any correct pairing of one controlled item and the one changed item.
  5. Answer: Water that sits on top for a long time means the soil soaks water in slowly. A rain garden is built to hold a shallow pool only briefly, so with that soil the garden would stay flooded and overflow, and the crew should not fill the garden with that soil alone. Accept any next test that changes one thing, such as adding more sand to the mix, loosening the packed soil, or making the garden bed deeper.
  6. Answer: A labeled drawing naming the atmosphere and the geosphere. Arrows on the yard side should point down into the soil, and arrows on the pavement side should point sideways across the surface toward a drain. Accept the hydrosphere in place of the atmosphere when the student's sentence explains that the rain itself is the water moving into the ground.

Differentiation

Support

Set up one column for these students in advance and let them run only the two remaining columns, so the timing routine is learned on a prepared example. Give them a data table with the column names and units already filled in, and pair each student with a partner who runs the stopwatch while they pour.

Extension

Ask these students to run a fourth column using a mix of their own design, stating the proportions before they build it and predicting where its time will fall against the other three. They should then explain whether the result matched their prediction and what that says about how much sand a rain garden mix needs.

ELL supports

Demonstrate the whole pour-and-time routine once with water and sand before any team begins, naming each action aloud as you do it. Provide picture labels for sand, soil, mix, pour, and soak in, and allow questions 3 through 6 to be answered with a labeled drawing plus a short phrase.

Extensions

Take the class outside after a rain to find one spot where water is standing and one spot where the ground looks dry within an hour, and have students explain the difference using their column results and the model they drew in question 6.