Worksheet Grade 6 Math

Coldspring Chlorine Residual Log: A Grade 6 Data Worksheet

A grade 6 data worksheet where students summarize a fictional town's chlorine test readings with mean, median, range, and percent within the safe target.

Grade: Grade 6
Subject: Math
Material: Worksheet
Time: 35 min
Prep: No prep
Materials: Calculator (optional)

Standards

6.SP.B.5 Common Core Math

Summarize numerical data sets in relation to their context, reporting the number of observations, describing the attribute measured, giving quantitative measures of center and variability, and relating the choice of measures to the shape of the distribution.

How this material aligns: Items 2 through 4 have students report the range, mean, and median of a ten-reading sample set and item 9 relates the choice of measure to the outlier, exactly what this standard asks.

All materials for 6.SP.B.5 →

6.RP.A.3 Common Core Math

Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations, including finding a percent of a quantity and converting measurement units.

How this material aligns: Item 6 asks students to find what percent of the ten readings fall inside the target range, the find-a-percent-of-a-quantity reasoning at the center of this standard.

All materials for 6.RP.A.3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will find the mean, median, and range of a set of water test readings.
Students will find what percent of the readings fall within a safe target range.

Vocabulary

Key words: mean, median, range, residual, outlier

Teacher overview

Water systems add a small amount of chlorine to keep water safe all the way to each home. The amount left in the water is called the residual, and operators test it at homes across town. This worksheet uses a fictional set of ten readings so students can summarize realistic data with mean, median, range, and percent. As a teaching note, item 9 is the key discussion: one very low reading pulls the mean below most homes, which is why the median can describe a "typical" home better.

Coldspring Chlorine Residual Log: A Grade 6 Data Worksheet — Grade 6 Math

Name: ____________________________ Date: ______________

Student Worksheet

An operator in the fictional town of Coldspring measured the chlorine residual at 10 homes. The readings, in mg/L, were: 1.0, 0.8, 1.2, 0.9, 0.1, 1.1, 1.4, 0.9, 1.0, 1.1. The system tries to keep every home between 0.2 and 2.0 mg/L. The safety limit for chlorine is 4.0 mg/L.

Put the 10 readings in order from least to greatest.
What is the range of the readings? (The range is the largest reading minus the smallest.)
What is the mean of the 10 readings? Add them up and divide by 10.
What is the median of the 10 readings? Find the middle when they are in order.
How many of the 10 readings fall within the target range of 0.2 to 2.0 mg/L?
What percent of the readings are within the target range?
One home read 0.1 mg/L. Is that above or below the target range, and by how much?
The highest reading was 1.4 mg/L. How far below the 4.0 mg/L safety limit is that reading?
The mean and median are not equal here. Explain which one better describes a typical home, and why.
Suppose the operator re-tests the 0.1 home and it now reads 0.6 mg/L. What percent of the 10 readings are within the target range now?

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: 0.1, 0.8, 0.9, 0.9, 1.0, 1.0, 1.1, 1.1, 1.2, 1.4 mg/L. Sorting puts the one low reading, 0.1, first and the highest, 1.4, last.
Answer: 1.3 mg/L. Largest 1.4 − smallest 0.1 = 1.3 mg/L.
Answer: 0.95 mg/L. The 10 readings add to 9.5; 9.5 ÷ 10 = 0.95 mg/L.
Answer: 1.0 mg/L. With 10 readings in order, the median is the mean of the 5th and 6th values: (1.0 + 1.0) ÷ 2 = 1.0 mg/L.
Answer: 9 readings. Every reading except 0.1 is between 0.2 and 2.0, so 9 of the 10 are within range.
Answer: 90 percent. 9 within range ÷ 10 total = 0.9, which is 90 percent.
Answer: Below, by 0.1 mg/L. The target starts at 0.2, and 0.2 − 0.1 = 0.1 mg/L below the range.
Answer: 2.6 mg/L. 4.0 mg/L limit − 1.4 mg/L reading = 2.6 mg/L below the limit.
Answer: The median (1.0 mg/L). The single very low reading of 0.1 pulls the mean down to 0.95, below six of the ten homes, so the median better shows a typical home.
Answer: 100 percent. With the re-test at 0.6, all 10 readings are now between 0.2 and 2.0, so 10 ÷ 10 = 100 percent.

Differentiation

Support

Give students a number line marked from 0 to 2.0 mg/L with the target band shaded, and have them plot the 10 readings before they compute. Provide the sum (9.5) for item 3 so they can focus on the division. Review that "median" means the middle value in an ordered list.

Extension

Ask students to add an 11th reading that would raise the mean but leave the median unchanged, then show both new values with their work. Have them explain how one reading can change the mean more than the median.

ELL supports

Pre-teach "residual," "mean," "median," and "range" with a small picture glossary. Provide a sentence frame for item 9: "The ___ describes a typical home better because the low reading ___." Allow students to point to values on the number line to show answers to items 5 and 7.