Lab / experiment Grade 4 Health & Consumer Science
Dip, Scoop, or Pour: The Merrivane Owls' Dugout Water Cooler
A grade 4 health lab in which students coat their fingertips with cinnamon as a stand-in for germs and test three ways of serving water from a shared team cooler.
Objectives
- Students will run a fair test comparing how dipping, scooping, and pouring move a germ stand-in into a shared water supply.
- Students will use their speck ratings to rank the three serving methods and identify a failure point in one setup.
- Students will explain how germs on one person's hands can reach everyone who drinks from a shared cooler.
Vocabulary
Key words: germ, contaminate, shared supply, fair test, variable, failure point
Teacher overview
Youth sports teams often share one large water cooler, and the way players get water out of it affects whether germs from one pair of hands reach the whole team. In this lab students act as the fictional Merrivane Owls softball team. They press their fingertips into ground cinnamon, which stands in for germs, serve water from a shared supply in three different ways, and rate how many specks end up in the water the rest of the team would drink. The health behavior the lab supports is simple and practical: pour from a spout or tap, keep hands and cup rims out of shared water, and wash hands before handling anything the group will drink.
A misconception worth addressing directly is that water is safe to share as long as it looks clear. Cinnamon specks are easy to see, while the germs that cause stomach illness are far too small to see, so a speck-free tub in this lab shows only that the serving method kept hands out of the water, and it says nothing about whether a real cooler is germ-free. A second misconception is that dipping a cup puts only the person who dipped at risk; question 8 asks students to explain why one set of hands in a shared supply affects every person who drinks from it. Cinnamon can irritate eyes and some skin, so check for cinnamon allergies before the lab, keep gloves on hand, and remind students not to touch their faces during the trials.
Procedure
Step 1, safety first. Do not drink or taste any water in this lab. Keep the cinnamon away from your eyes and face. If cinnamon bothers your skin, wear a glove. Wipe up spills right away so no one slips.
Step 2, meet the team. Your group is the Merrivane Owls softball team. The team shares one cooler in the dugout. Your job is to find the way of getting water that keeps the shared water cleanest. The cinnamon stands in for germs on your hands. Real germs are too small to see.
Step 3, learn the three methods.
- Dip. Hold a paper cup and dip it right into the open tub.
- Scoop. Hold the ladle by its handle. Scoop water and pour it into your cup.
- Pour. Lift the pitcher by its handle and pour water into your cup.
Step 4, keep the test fair. Every trial starts with 500 mL of clean tap water. Every trial has 4 servings. If your group has 3 people, one person serves twice. Before each serving, the server presses the fingertips of one hand flat on the cinnamon plate one time. Then the server taps those fingers once on the edge of the plate. Only the method changes from trial to trial.
Step 5, run a Dip trial. Measure 500 mL of water into the open tub. Take turns until all 4 servings are done. Pour each served cup into the used-water bucket.
Step 6, check for specks. Set the checking tub on the white paper. Pour the water left in the open tub into the checking tub. Count the specks you can see. Use the Speck Scale below to pick a rating. Write the rating in the data table.
| Rating | What you see in the checking tub |
|---|---|
| 0 | No specks |
| 1 | 1 to 5 specks |
| 2 | 6 to 15 specks |
| 3 | 16 to 30 specks |
| 4 | More than 30 specks |
Step 7, clean up between trials. Empty and rinse the checking tub and the tub or pitcher you served from. Wipe your fingertips with a damp paper towel.
Step 8, run the Scoop and Pour trials. Repeat Steps 5 to 7 for Scoop, then for Pour. For Scoop, fill the open tub and use the ladle. For Pour, fill the pitcher and pour from it. After the Pour trial, pour the water left in the pitcher into the checking tub to count.
Step 9, run each method again. Do Steps 5 to 8 one more time. Now each method has 2 trials. Add the two ratings for each method to find its total.
Step 10, improve one setup (Session 2). Look at your Dip or Scoop results. Find one moment when specks got into the shared water. Change one thing to stop it. For example, you could hang the ladle on the side of the tub, or put a lid with a small opening on the tub. Run one new trial with your change. Write the rating in the Improved row.
Step 11, share with the class. Write your three method totals on the class chart.
Step 12, wash your hands. Use soap and water. Scrub well before you touch food or your face.
Data & Analysis
| Method | Trial 1 rating (0 to 4) | Trial 2 rating (0 to 4) | Total (add the two) |
|---|---|---|---|
| Dip | |||
| Scoop | |||
| Pour | |||
| Improved setup (one trial only) |
Under the table, write one sentence that tells what you changed in your improved setup.
- Which method had the highest total in your group? Use your table.
- Which method had the lowest total in your group?
- Subtract your lowest total from your highest total. What is the difference?
- Look at the class chart. Did most groups find the same order as your group, from the most specks to the fewest? Tell what the class results show.
- In our scenario, a class at another school added up all of its group totals. The Dip method scored 38 points. The Scoop method scored 15 points. How many more points did the Dip method score than the Scoop method?
- A failure point is a moment when specks got into the shared water even though the server was being careful. Name one failure point you saw. Tell which method it was and what happened.
- Compare your Improved rating with your two ratings for that same method before the change. Did your change help? Use your numbers to explain.
- Cinnamon is only a stand-in for germs. Explain why a germ in the shared cooler is a bigger problem for the team than a germ in one player's own cup.
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: The method with the largest total in the group's own table.
Accept any method that matches the table. Most groups find Dip highest, because fingers go into the shared water on every serving. - Answer: The method with the smallest total in the group's own table.
Accept any method that matches the table. Most groups find Pour lowest, often with a total of 0, because hands touch only the pitcher handle and never the stored water. - Answer: The group's highest total minus its lowest total.
Accept any difference that matches the group's table. For example, a group with a Dip total of 7 and a Pour total of 0 has a difference of 7. Each total runs from 0 to 8, so every correct difference falls between 0 and 8. - Answer: An answer that matches the class chart.
The usual pattern is Dip with the most specks, Scoop in the middle, and Pour with the fewest. A strong answer says whether any group broke the pattern and offers a reason, such as a server touching the bowl of the ladle. - Answer: 23 points.
Subtract the Scoop total from the Dip total: 38 minus 15 equals 23. Check by adding: 15 plus 23 equals 38. - Answer: Any real observation tied to one method.
Common failure points include cinnamon falling off fingers into the open tub while a server reaches for the ladle, a finger touching the bowl of the ladle, the ladle handle sliding down into the water, the rim of a dipped cup scraping specks off the server's fingers, and a finger curling over the rim of the pitcher while pouring. - Answer: A comparison that uses the group's own Improved rating and its earlier ratings for the same method.
A lower Improved rating means the change helped. A rating that stayed the same is also acceptable when the student names a failure point the change did not fix. - Answer: Everyone drinks from the shared cooler, so a germ from one player's hands can reach every player on the team.
A germ in one player's own cup reaches only that player. Accept any answer that makes this one-to-many point in the student's own words.
Differentiation
Support
Give each group three picture cards showing the Dip, Scoop, and Pour methods, and tape the Speck Scale to the table beside the checking tub. Let partners count specks together, one pointing and one tallying, and accept spoken answers to questions 6 and 8 recorded by the teacher. For question 3, provide a number line from 0 to 8 so students can count up from the lower total to the higher one.
Extension
Add a fourth setup that tests a habit many players have: pressing the mouth of a water bottle against a spout while filling it. Students dab cinnamon on the rim of a clean bottle, fill it from the pitcher while the rim touches the spout, and then pour a fresh cup from the same spout and check that cup for specks. Ask them to write two sentences explaining what their result means for a team that fills bottles from one jug.
ELL supports
Pre-teach "dip," "scoop," "pour," "germ," and "shared" with the picture cards and a quick demonstration of each motion. Provide sentence frames for the analysis questions: "The ___ method had the most specks because ___." and "A germ in the cooler is a problem for the whole team because ___."
Extensions
Have each group write a three-rule sign for the Merrivane Owls' dugout cooler, using its own results to justify each rule, and post the signs near the classroom sink or the gym water fountain. Groups can compare their rules and agree on one class version.