UNIT: MEASUREMENT

ACT-Based Reading: Analyzing Technical Texts

OBJECTIVE:

This activity strengthens students’ ability to interpret technical diagrams, measurement instructions, and data tables. By analyzing complex instructions, they improve reading comprehension, precision in following steps, and real-world problem-solving skills relevant to ACT success. by interpreting technical diagrams, measurement instructions, and data tables. By breaking down complex instructions, students improve their ability to extract key information, follow precise steps, and apply their understanding to real-world scenarios.

STUDENT DIRECTIONS:

Goals:

In this activity, you'll improve your ability to analyze technical writing, diagrams, and data tables—skills that are directly tested on the ACT Reading section and essential in STEM careers. You'll learn how to interpret complex measurement-related texts and apply that information to answer ACT-style questions with confidence.

Step 1: Pre-Read and Predict

Skim the passage title, headings, and data table.

Predict what kind of information you might learn about rulers, tape measures, and digital calipers.

Write down 1–2 questions you think the passage will answer.

Step 2: Read and Annotate the Passage

As you read the technical passage titled Understanding Measurement Tools:

Underline or highlight key terms like "accuracy," "precision," "measurement tool," and "engineering."

Circle any unfamiliar words (look them up after reading).

Make margin notes about the strengths and limitations of each tool.

Step 3: Analyze the Comparison Table

Review the table comparing ruler, tape measure, and digital caliper.

Use a different color highlighter to mark each tool's:

Accuracy

Precision

Common uses

On a blank sheet or your worksheet, match each tool to the type of task it would be best for.
Example: Measuring a car part → ___? (Answer: Digital Caliper)

Technical Passage:

Understanding Measurement Tools

Accurate measurement is essential in science, engineering, and construction. Three commonly used tools for measuring length and dimensions are rulers, digital calipers, and tape measures. Each tool serves a distinct purpose, offering different levels of precision and accuracy depending on the measurement needs.

A ruler is a basic tool used for measuring straight-line distances. Typically marked in inches and centimeters, rulers are convenient for quick measurements but may lack precision for very small or curved objects. Their accuracy is limited by the smallest marked unit, usually millimeters or 1/16 of an inch.

A digital caliper provides much greater precision than a ruler. It is commonly used in engineering and manufacturing, capable of measuring objects to the nearest 0.01 mm. Unlike rulers, digital calipers can measure both external and internal dimensions with high accuracy. The digital display minimizes human error, making calipers ideal for applications requiring exact specifications.

A tape measure is designed for measuring longer distances and larger objects, such as furniture, rooms, or construction materials. Unlike a ruler or caliper, a tape measure is flexible and retractable, making it suitable for measuring curved or irregular surfaces. However, its precision is generally lower than that of a digital caliper, as its smallest unit is typically 1/16 of an inch or 1 mm.

Understanding the appropriate tool for a given task is crucial in fields like engineering, architecture, and scientific research. Choosing the right instrument improves measurement accuracy, reduces error, and ensures consistency in calculations and technical applications.

Table: Comparing Measurement Tools

Measurement Tool	Accuracy	Precision	Common Uses
Ruler	±1 mm	Low	Basic length measurements, school projects
Tape Measure	±1 mm – 5 mm	Medium	Measuring large objects, construction, furniture sizing
Digital Caliper	±0.01 mm	High	Engineering, machining, small object measurements

ACT-Style Reading Questions:

Based on the passage, which tool is best for measuring the diameter of a small screw? (ACT Reading Score: 20-23)

Ruler

Tape Measure

Digital Caliper

Protractor

Why might an engineer prefer a digital caliper over a tape measure? (ACT Reading Score: 24-27)

Materials:

Technical passage explaining the differences in measurement tools

Table comparing accuracy, precision, and common uses of each tool