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Classroom activity Grade 4 Math

Rushlight Creek Sampling Route: A Six-Station Rotation

A grade 4 activity where teams rotate through six creek sampling stations, then use a printed site log to total bottles and minutes and pack coolers.

Objectives

  1. Students will add and multiply counts and time intervals recorded across six sampling stations.
  2. Students will interpret a remainder as one more cooler needed to carry every bottle.
  3. Students will explain why a testing crew samples a creek in more than one place.

Vocabulary

Key words: sample, station, site log, cooler, creek

Teacher overview

This is a six-station rotation for teams of four students, built around a fictional creek called Rushlight Creek that runs past a farm, a road culvert, and a school landing before reaching a lower weir. Each station in the classroom stands for one real sampling site along the creek, and teams move through the stations in order, the same way a testing crew drives a route from upstream to downstream. Moving through the stations in creek order, students see that a crew collects a different number of bottles and spends a different number of minutes at each place. The mathematics comes from a printed site log that every student keeps, so the totals do not depend on how fast any team actually moves.

Activity Directions

  1. Before class, post the six station signs around the room in this order: Station 1 Mill Bridge, Station 2 Stone Ford, Station 3 Otter Bend, Station 4 Culvert Road, Station 5 School Landing, Station 6 Lower Weir. Put a small set of clean empty bottles or cups at each station.

  2. Take 5 minutes at the start of class to group students into teams of four, assign each team a starting station, and hand out the student handout, which contains the site log the whole class will use.

  3. During that same setup time, explain the roles within a team: one collector who picks up the bottles, one recorder who reads the site log aloud, one timekeeper who watches the clock, and one reporter who will speak during the debrief. Roles rotate at each station so every student holds each job at least once.

  4. Run six rounds of 5 minutes each. At each station, the team reads the site log entry for that station, states out loud how many bottles the crew collected there and how many minutes the visit took, and then acts out the collection by picking up that many bottles.

  5. Call time at the end of each round and have teams move to the next station in numerical order. Teams at Station 6 rotate back to Station 1.

  6. The activity ends after every team has visited all six stations, which takes 30 minutes of rotation. Teams return to their seats.

  7. Give students 5 minutes to finish any questions on the handout that they have not answered yet, using the site log rather than their own timing.

  8. Close with a 5-minute debrief. Ask two reporters to share their answer to handout question 9, then ask the class the question in handout item 10 and take three responses before summarizing.

Rushlight Creek Sampling Route: A Six-Station Rotation — Grade 4 Math
Name: ____________________________ Date: ______________

Student Handout

The Rushlight Creek site log for one sampling day:

Station Site Bottles collected Minutes at the site
1 Mill Bridge 8 12
2 Stone Ford 6 9
3 Otter Bend 12 15
4 Culvert Road 7 11
5 School Landing 9 14
6 Lower Weir 5 8

  1. How many bottles did the crew collect at all six stations together?

  2. How many minutes did the crew spend at all six stations together?

  3. Which station took the most minutes?

  4. How many more bottles were collected at Station 3 than at Station 6?

  5. Every bottle needs 3 labels. How many labels are needed for all of the bottles from question 1?

  6. The crew visits all six stations 4 times in one month. How many station visits is that?

  7. A visit to Station 1 takes 12 minutes. How many minutes do 4 visits to Station 1 take?

  8. On sampling day the crew also spends 25 minutes driving between stations. Using your answer from question 2, how many minutes does the whole day take?

  9. One cooler holds 9 bottles. How many coolers does the crew need to carry all of the bottles from question 1?

  10. Explain why the crew takes samples at six places along Rushlight Creek instead of only one.

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: 47 bottles.
    8 + 6 + 12 + 7 + 9 + 5. Adding in order gives 14, then 26, then 33, then 42, then 47 bottles.

  2. Answer: 69 minutes.
    12 + 9 + 15 + 11 + 14 + 8. Adding in order gives 21, then 36, then 47, then 61, then 69 minutes.

  3. Answer: Station 3, Otter Bend.
    Otter Bend took 15 minutes, which is more than any other station in the log.

  4. Answer: 7 bottles.
    Station 3 had 12 bottles and Station 6 had 5, so 12 − 5 = 7 more bottles.

  5. Answer: 141 labels.
    47 × 3. Splitting 47 into 40 + 7 gives 40 × 3 = 120 and 7 × 3 = 21, and 120 + 21 = 141 labels.

  6. Answer: 24 visits.
    Six stations visited 4 times each is 6 × 4 = 24 station visits.

  7. Answer: 48 minutes.
    12 × 4 = 48 minutes across the four visits to Station 1.

  8. Answer: 94 minutes.
    The sampling time is 69 minutes and driving adds 25 minutes, so 69 + 25 = 94 minutes.

  9. Answer: 6 coolers.
    47 ÷ 9 gives 5 with a remainder of 2, because 9 × 5 = 45. The last 2 bottles still need a cooler, so the crew needs 6 in all.

  10. Answer: Water changes as the creek flows past different places, so one sample cannot show what is happening along the whole creek.
    Accept any answer that names a difference between sites, such as a farm upstream or a road culvert, and connects it to needing more than one sample.

Differentiation

Support

Highlight the two columns of the site log in different colors so students can see which numbers answer a bottle question and which answer a minute question. Provide counters in groups of nine for question 9 so the two leftover bottles are visible before the division is written.

Extension

Ask students to design a seventh station for the route, choose a bottle count and a visit time for it, and rewrite the answers to questions 1, 2, and 9 with the new station included.

ELL supports

Pre-teach "sample," "station," "site log," and "cooler" by holding up a bottle and a cooler while pointing to the matching row of the table. Provide the sentence frame: At Station ___ the crew collected ___ bottles in ___ minutes.

Extensions

Have students mark the six stations on a simple hand-drawn creek map in order from upstream to downstream, then write one sentence predicting which station would show the most sediment after a heavy rain.