Students will estimate lengths of everyday objects and will use the vocabulary “inches”, “feet”, “centimeters” and “meters”

**Class:** Second Grade

**Duration:** One class period of 45 minutes

**Materials:**

- Rulers
- Meter sticks
- Chart paper

**Key Vocabulary:** estimate, length, long, inch, foot/feet, centimeter, meter

**Objectives:** Students will use correct vocabulary when estimating lengths of objects.

**Standards Met: **2.MD.3 Estimate lengths using units of inches, feet, centimeters, and meters.

### Lesson Introduction

Bring in differently sized shoes (you may borrow a shoe or two from a colleague for the purposes of this introduction if you wish!) and ask students which they think will fit your foot. You can try them on for humor’s sake, or tell them that they are going to be estimating in class today - whose shoe is whose? This introduction can also be done with any other article of clothing, obviously.

### Step-by-Step Procedure

- Have students select 10 ordinary classroom or playground objects for the class to measure. Write these objects on the chart paper or on the board. Make sure to leave plenty of space after the name of each object, because you will be recording the information the students give you.
- Begin by demonstrating how to estimate with the ruler and meter stick. Choose one object and discuss with students - is this going to be longer than the ruler? Much longer? Would this be closer to two rulers? Or is it shorter? As you think aloud, have them suggest answers to your questions.
- Record your estimation, then have students check your answer. This is a good time to remind them about estimation, and how getting close to the exact answer is our goal. We do not need to be "right" every single time. What we want is an approximation, not the real answer. Estimation is something they'll be using in their daily lives (at the grocery store, etc.) so do highlight the importance of this skill to them.
- Have a student model an estimation of the second object. For this part of the lesson, choose a student who you think may be able to think aloud in a way similar to your modeling in the previous step. Lead them to describe how they got their answer to the class. After they have finished, write the estimate on the board and have another student or two check their answer for appropriateness.

- In pairs or small groups, students should finish estimating the chart of objects. Record their answers on chart paper.
- Discuss the estimates to see if they are appropriate. These don’t need to be correct, they just need to make sense. (For example, 100 meters isn’t an appropriate estimate for the length of their pencil.)
- Then have students measure their classroom objects and see how close they came to their estimates.
- In closing, discuss with the class when they might need to use estimation in their lives. Make sure to tell them when you make estimates in your personal and professional life.

### Homework/Assessment

An interesting experiment is to take this lesson home and do it with a sibling or parent. Students can choose five items in their houses and estimate their length. Compare the estimates with those of family members.

### Evaluation

Continue to put estimation in your daily or weekly routine. Take notes on students who are struggling with appropriate estimates.