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Worksheet Grade 6 Social Studies & Civics

Whitlock Creek Watch: Reading a Citizen Water-Testing Data Table

A grade 6 worksheet in which students summarize a fictional volunteer group's weekly creek-testing data and decide what evidence to bring to a town council meeting.

Objectives

  1. Students will calculate the mean of a set of water-quality readings.
  2. Students will compare data to a stated benchmark and determine what percent of readings fall below it.
  3. Students will explain why repeated citizen testing provides stronger evidence than a single test.

Vocabulary

Dissolved oxygen
Dissolved oxygen is the oxygen gas mixed into water that fish and other underwater animals breathe. Cold, moving water holds more oxygen than warm, still water.
Citizen science
Ordinary people helping to do real science, like the Flint residents who collected water samples that helped prove their water was unsafe.

Also: benchmark, deliberative process

Teacher overview

This worksheet follows a fictional volunteer group, Whitlock Creek Watch, that tests a local stream every week and brings its findings to the town council. Students summarize five weeks of dissolved-oxygen and pH readings, compare the data to two familiar water-quality benchmarks, and decide what the numbers would mean to a council deciding whether to fund new stormwater protections. A common misconception is that one bad reading proves a stream is polluted; the exercise is built so students see why council members look for a pattern across several weeks instead of a single number.

Whitlock Creek Watch: Reading a Citizen Water-Testing Data Table — Grade 6 Social Studies & Civics
Name: ____________________________ Date: ______________

Student Worksheet

Whitlock Creek Watch is a fictional volunteer group used for this worksheet. Each week, its members test the creek at the same spot. They record two numbers: dissolved oxygen (DO) and pH. Most fish need DO above 5 mg/L to survive. Water treatment plants use a secondary standard of pH 6.5 to 8.5 for water that reaches household taps. The volunteers use that same familiar range as a general benchmark when they check the creek.

Week Dissolved oxygen (mg/L) pH
1 7.0 7.2
2 5.5 7.6
3 4.0 8.6
4 6.0 7.0
5 4.5 7.4
  1. Calculate the mean dissolved-oxygen reading across all five weeks.
  2. How many of the five weekly DO readings fall below the 5 mg/L benchmark that most fish need?
  3. What percent of the five weekly DO readings fall below the 5 mg/L benchmark?
  4. Which week's pH reading falls outside the 6.5 to 8.5 range, and by how much?
  5. Whitlock Creek Watch plans to present this data at the town council meeting. Write one sentence a volunteer could say to summarize the DO data for council members who have not seen the numbers.
  6. Suppose the town council only orders a stormwater inspection if DO drops below 5 mg/L for two weeks in a row. Does this five-week data set meet that rule? Use the table to explain your answer.
  7. If the volunteers tested the creek every day instead of once a week, how many total tests would they run over this same five-week period?
  8. Explain why a town council would trust five weeks of volunteer data more than one test from a single day. Write one or two sentences.
  9. Using your answer to item 1, is Whitlock Creek's average DO level above or below what most fish need, and by how many mg/L?

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: 5.4 mg/L.
    7.0 + 5.5 + 4.0 + 6.0 + 4.5 = 27.0. 27.0 ÷ 5 weeks = 5.4 mg/L.
  2. Answer: 2 weeks.
    Week 3 (4.0 mg/L) and Week 5 (4.5 mg/L) are both below 5 mg/L.
  3. Answer: 40 percent.
    2 of 5 readings are below the benchmark. 2 ÷ 5 × 100 = 40 percent.
  4. Answer: Week 3, by 0.1.
    Week 3's pH of 8.6 is 0.1 above the upper limit of 8.5.
  5. Answer: Answers will vary. A strong response states the mean DO clearly, such as "Over five weeks, our creek's average dissolved oxygen was 5.4 mg/L, just above what fish need to survive."
  6. Answer: No, it does not meet the requirement.
    Weeks 3 and 5 fall below 5 mg/L, but Week 4 (6.0 mg/L) sits between them, so the low readings are not two weeks in a row.
  7. Answer: 35 tests.
    5 weeks × 7 days per week = 35 tests.
  8. Answer: Answers will vary. A strong response explains that a single reading could be an unusual day, while five weeks of consistent data shows a pattern the council can trust as reliable evidence.
  9. Answer: Above, by 0.4 mg/L.
    The mean of 5.4 mg/L is 5.4 − 5.0 = 0.4 mg/L above the 5 mg/L benchmark.

Differentiation

Support (below grade level)

Provide the sum of the five DO readings (27.0) already calculated so students only need to complete the division step in item 1, and highlight the two weeks below 5 mg/L in the table before students answer items 2 and 3.

Extension (above grade level)

Ask students to calculate the range (highest minus lowest reading) for both the DO and pH data sets, then write a sentence explaining which measurement, DO or pH, varied more across the five weeks and what that might mean for the council's decision.

ELL supports

Pre-teach "dissolved oxygen," "benchmark," and "council" with a simple visual (a fish and a thermometer-style scale showing the 5 mg/L line). Allow item 5 and item 8 to be answered as a spoken summary to a partner, with a sentence starter provided: "Our data shows ___, so the council should ___."