Unit Plan 23 (Grade 3 Math): Line Plots—Lengths to 1/2 and 1/4 Inch
Measure to the nearest 1/2 and 1/4 inch, create clear line plots, and solve “how many more/fewer” comparison problems using precise units and mathematical reasoning.
Focus: Measure to the nearest 1/2 and 1/4 inch; display data on line plots; solve “how many more/less” problems.
Grade Level: 3
Subject Area: Mathematics (Measurement & Data • Operations)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
Students become careful measurers, then turn their measurements into line plots that tell a story. They practice reading scales, labeling units, and answering comparison questions like “how many more/fewer,” explaining each step with precise math language.
Essential Questions
- How does careful measurement (starting at zero, reading tick marks) change the results I get?
- How do the scale and units on a line plot affect what I can see and say?
- What does “how many more/fewer” really mean when I read a data display?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Measure objects to the nearest 1/2 inch and 1/4 inch and record data accurately.
- Construct clear line plots with a chosen scale, labels, and title.
- Answer “how many more/fewer” and total/compare questions by interpreting the plot and computing correctly.
- Explain measurement and comparison reasoning using precise units and vocabulary.
- Choose and use appropriate tools (rulers, templates) and check for reasonableness and errors.
Standards Alignment — CCSS Grade 3
- 3.MD.4: Generate measurement data by measuring to the nearest 1/2 and 1/4 inch; display measurement data in a line plot.
- 3.OA.3: Use multiplication/division within 100 to solve word problems in situations involving equal groups/compare (applied to “how many more/fewer” on plots).
- MP.5: Use appropriate tools strategically (ruler selection, scale choice).
- MP.6: Attend to precision (units, labels, tick marks).
- MP.2/MP.4: Reason abstractly/quantitatively; model with mathematics (plots that represent the situation).
Success Criteria — Student Language
- I can measure to the nearest 1/4 inch and record it with the correct unit.
- I can build a line plot with a clear scale, labels, and a title.
- I can answer “how many more/fewer” and explain how I know using evidence from the plot.