Inch rulers, 1 per student; objects to measure, 1 per pair of students; Recording Sheet, 1 per student.

Students need several experiences with an inch ruler prior to this small group lesson:

• Draw a line on the board that is about 4 and inches long. Draw another line underneath it that is one inch long. Tell students the shorter line is one inch long, and that you want them to think about how long the first line might be in inches. Give them about 15 seconds to think quietly. Then ask them to whisper to a partner what they were thinking (about 15-20 seconds). Finally, ask students to share what they discussed with their partners (about 1-2 minutes). When students share their estimates, ask students to tell why they chose a specific estimate. Record students' estimates on the board.
• Ask a student to measure the line with an inch ruler.
  • If student says it is between 4 and 5 inches ask, "How will you decide which is the nearest inch?" "Is it closer to 4 inches or 5 inches?" Introduce the vocabulary "about".
• Refer back to the recorded estimates. Ask, "Did anyone estimate 4 inches?" Did anyone estimate 5 inches?" "Were both close estimates? Why?"
• Give students Recording Sheet 1. Students work in pairs to estimate to the nearest inch the length of objects you have gathered before the lesson. There should be an object for every pair of students. Students draw the objects and write their estimates on the recording sheet. (No rulers are used during this part of the lesson.)
• After estimates have been recorded, ask students to measure the objects with inch rulers. Remind them to measure to the nearest inch.
• Close the lesson by asking students to talk about their estimates and actual measurements. Were they close? What helped them in thinking about their estimates?

Recording Sheet http://mdk12.org/instruction/lessons/images/Gr1_3B1aLS1.pdf