Grade: Elementary
Subject: Mathematics

#1380. Estimation

Mathematics, level: Elementary
Posted Tue Nov 7 06:25:48 PST 2000 by Angela Brallier (
Indiana University of Pennsylvania, United States
Materials Required: Encyclopedia, paper/worksheet,pictures of dinosaurs
Activity Time: one hour
Concepts Taught: Estimated guesses

Subject: Math
Grade: 3rd
Time Allotted: 1 hour


The purpose of this lesson is for the students to get an understanding of estimation. Estimation is an educated guess based on one's impressions, an opinion. Students will also learn more about measuring and how looking at various object size and shape can help form ones guess towards estimation. Students will further investigate estimation through an experiment performed by a hand on activity.
Students have some background knowledge and experience for this particular lesson. The students are familiar with measuring and estimated guesses.


1. TWL explain the meaning of estimation.
PI: Before actual measurements are given students will use prior knowledge to estimate how large they believe each body part is.
2. TWL Verify their estimation
PI: Each student will check the measurement in an Encyclopedia for actual answers.


* Encyclopedia
* Pictures of dinosaurs
* Worksheets or paper


1. Estimated guesses are formed from what they already know.
2. Estimated guesses may be very close or far away from actual


A. Introduction and Motivation

The teacher will ask the students how big they are thought the classroom is. Each student will have the opportunity to use their prior knowledge to give an estimation of the size of the room. Teacher can make a list of estimations on the board and ask questions to explore how they came to this rational. To help them better understand this concept each student will pick two objects in the room such as a desk or door and write down there estimation. Then they will use a ruler to get the actual measurement. This will give them practice and clarify any misunderstanding about estimation.

B. Lesson Body

Teacher will have pictures of eight different types of dinosaurs placed on each student's desk. Individually the students will examine the picture and estimate the size they think the dinosaur are if they were real. Each student will write down his or her answer. Afterwards students will check an Encyclopedia to find the actual measurements of the dinosaurs.

C. Lesson Closure

Once everyone has gotten their results the teacher will then ask the students to volunteer there answers both estimated and actual. Students will compare answers as a class. The teacher will discuss their results.


A. Student Assessment

1. Assessment Plan

The teacher will do an informal assessment by observing student estimating the dinosaur and the having a class discussion about their estimated guesses compared to the real answer. Were the students close?

2. Reflection on Assessment of Student Performance