Choose a Measurement Unit

Overview

In this fourth lesson of the unit, students build on their understanding of measuring length by choosing a sensible customary unit for different objects and spaces. Through modeling, sorting, and visual task cards, students explain why inches, feet, or yards is reasonable.

Learning intentions

• Students will be able to select inches, feet, or yards for a measurement problem.
• Students will be able to use the words unit, inches, feet, yards, and reasonable.
• Students will be able to explain their choice by speaking, pointing, drawing, or using a sentence frame.
• Students will be able to estimate a measurement when prompted.

Success criteria

• I can match at least four of five objects to a sensible unit.
• I can choose inches, feet, or yards.
• I can explain that the unit should be reasonable for the object’s size.
• I can make a sensible estimate using my chosen unit.

Curriculum links

• Measurement and Data — select appropriate tools and units to measure length.
• Measurement and Data — compare lengths and describe how much longer one object is than another using standard units.
• Measurement and Data — solve length problems using addition and subtraction within 100.
• Measurement and Data — represent whole numbers and sums or differences on a number line.

Lesson structure (30 minutes)

1. 0–3 min · Hook and learning intention. Open with the opening question and object images and ask, “Would you measure a soccer field in inches?” Students give a thumbs-up or thumbs-down, then repeat: “I can choose a reasonable measurement unit.” Briefly introduce unit, inches, feet, yards, and reasonable using gestures and real objects.

2. 3–8 min · Mini-lesson 1: I do. Display the unit comparison slides and think aloud while matching pictures of a pencil, hand span, room, school bus, and soccer field to large unit cards. Show an inch ruler, a 1-foot ruler or strip, and a yardstick; explain that smaller objects usually need smaller units and larger spaces need larger units. Students echo the vocabulary and indicate their choices by pointing.

3. 8–15 min · Mini-lesson 1: We do. Place three labeled hoops or floor areas for inches, feet, and yards. Students work together to sort teacher-prepared picture cards, using the sorting directions and discussion prompt as a visual guide. After each card, ask, “Is this reasonable? Why?” Students justify with a sentence frame: “I chose ___ because ___ is about this size.”

4. 15–18 min · Mini-lesson 2: Reconnect and model. Revisit the transition and worked-example slide. Model a visual “Which unit?” task card, first naming the object, then considering its size, choosing a unit, and estimating a number. Students practice the routine with a partner: “Look, think, choose, explain.”

5. 18–26 min · Mini-lesson 2: You do. Distribute the visual Which Unit? practice sheet and provide five visual task cards or display them one at a time using the independent task slides. Students select inches, feet, or yards for each object and explain by pointing, speaking, circling, or drawing; invite an estimate for one or two objects. Confer individually with the five students and ask, “What makes your unit reasonable?”

6. 26–30 min · Share and assess. Display the final review and exit prompt. Students hold up an inch, foot, or yard card for one final example and complete a brief oral or pointing exit check: pencil, room, soccer field, hand span, and school bus. Celebrate the strategy: “Choose a unit that fits the size.”

Resources

• the complete measurement unit slide deck
• the visual Which Unit? practice sheet
• Inch ruler and 1-foot ruler or measuring strip
• Yardstick or 1-yard measuring strip
• Three labeled hoops or floor signs: inches, feet, yards
• Unit cards with consistent colors and large symbols
• Picture cards for a pencil, hand span, book, table, room, school bus, and soccer field
• Five visual “Which unit?” task cards
• Optional response cards for inches, feet, and yards

Assessment

• During sorting, listen for students who connect unit size to object size and record whether each student can justify a choice.
• Review the five worksheet or task-card responses. The target is at least four correct matches out of five: pencil—inch; room—foot; soccer field—yard; hand span—inch; school bus—yard.
• Use the final oral or pointing check to identify students needing more practice. Accept speech, pointing, circling, or drawing as evidence of understanding.

Differentiation

• Begin with familiar real objects and model one clear comparison before introducing less familiar spaces. Offer only two unit choices to students who need reduced cognitive load, then add the third choice when ready.
• Provide peer support in the group of five, sentence frames such as “___ is reasonable because ___,” and unit cards students can hold or point to.
• For students ready for extension, ask, “About how many inches, feet, or yards might it be?” Accept an estimate and discuss whether it is reasonable rather than requiring exact measurement.
• For dyslexia-friendly access, read every card and direction aloud, use large print and symbols, keep inch/foot/yard colors consistent, limit text, and allow students to respond by speech, pointing, matching, or circling instead of writing.