Make learning how to estimate fun by using Shodor's computer applets. This lesson combines the use of four different computer estimation applets with several classroom estimation activities. Students can estimate arithmetic expressions, counting objects, length, and area.

Upon completion of this lesson, students will:

• practice estimation with computation, counting, length, and area

Technological: Students must be able to:
• perform basic mouse manipulations such as point, click and drag
• use a browser for experimenting with the activities

Students will need:

• access to a browser
• paper and pencil

Teacher should tape several shapes throughout the classroom for students to estimate area. Also prepare a jar full of jelly beans for students to estimate number of beans in the jar.

1. Focus and Review
   Have the students guess how many jelly beans are in a jar.
   
   
   
2. Objectives
   Students learn what estimation means and refine their estimation skills through several estimation activities.
   
   
   
3. Teacher Input
   
   • After the students have had a chance to write down their guess, have them raise their hands, so that you can call on a few students to explain the method they used to formulate their guess.
   • The teacher should know the correct answers and hone in on those students giving the correct answers.
   • Expand on students' methods and explain that these are forms of estimation.
   
   
4. Guided Practice
   
   • Have some pre-drawn or pre-taped shapes located around the room.
   • Have the students estimate the area of each shape in square ft and in square cm.
   • Have the students open the More or Less Estimator applet
   • Work through a few problems as a class, so that students can become familiar with the applet.
   
   
5. Independent Practice
   
   • Have the students take turns using the More or Less Estimator applet with a partner for about five minutes.
   • Once the students have had time to become proficient with the More or Less Estimator applet have them work with the Comparison Estimator applet for about five minutes.
   • Next have the students work with the Estimator applet for five minutes.
   • Finally have the class spend five minutes playing Estimator Four applet.
   • To ensure the students are on task you can circulate through the room monitoring their progress.
   • You may also want to have the students copy a problem from each applet that they found challenging.
   
   
6. Closure
   
   • Address any remaining questions the students have about the different estimating methods.
   • Have students discuss the various methods they used when estimating.
   
   

• Have the students calculate percent error.
• Examine the percent error calculations as a class.
• Discuss which estimation methods had the lowest percent error and why.