Introduction

At the end of this task, students will be able to:

• model decimals using base ten blocks
• model decimal addition and subtraction using base ten blocks
  
• transfer the model of base ten blocks to paper using numbers
  
• perform decimal addition and subtraction problems

Students will use the following website to help them model their decimals: http://nlvm.usu.edu/en/nav/vlibrary.html

Sub-activity #1:Modeling Decimals using Base Ten Blocks

1. Click on the worksheet #1: Modeling Decimals 
2. Save to Desktop and Print out 
3. Go to http://nlvm.usu.edu/en/nav/frames_asid_152_g_3_t_1.html
4. Set the number of decimal places to "2" and number of columns to "3"
5. Practice modeling the decimals on the virtual mat and then transfer your answers to the chart on worksheet #1

1. Go to the following website to activate the virtual blocks: http://nlvm.usu.edu/en/nav/frames_asid_264_g_3_t_1.html
2. Set the Decimal Places to "2" and the Columns to "3"
3. Click on worksheet #2: Adding and Subtracting 

The following rubric will be used to assess the webquest:

	Does Not       Meet 1	Meets 2	Exceeds 3	Score
Completion of Worksheet #1 using the Virtual Base Ten Blocks	Did not complete   the worksheet Did not use the website to assist in modeling the decimals	Completed the worksheet but did not use the website to assist in modeling the decimals	Completed the worksheet and thoroughly used the website to assist in modeling the decimals
Completion of Worksheet #2 using the Virtual Base Ten Blocks	Did not complete   the worksheet Did not use the website to assist in modeling the decimals	Completed the worksheet but did not use the website to assist in modeling the decimals	Completed the worksheet and thoroughly used the website to assist in modeling the decimals
Completion of 10 additional addition and subtraction problems in notebook	Completed less than 6 problems and completed the majority of the problems incorrectly	Completed 6-10 problems Completed some problems incorrectly	Completed all 10 problems (5 addition and 5 subtraction) and completed most of them correctly

At the conclusion of the lesson, students should be able to:

• Use the base ten blocks effectively on the virtual manipulatives website
• Model Decimals using base ten blocks
• Model Adding and Subtracting Deciamls using base ten blocks
• Add and Subtract decimals