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Addingand Subtracting Decimals

A WebQuest for 5th-7th Grade Math

Decimals Webquest

This project incorporates a fun, educational way to model, add, and subtract decimals. Students will use interactive base ten blocks from the Virtual Manipulatives website in order to record the decimals/decimal operations that they model.

Introduction

In this activity, you will be using base ten blocks on the Virtual Manipulatives website in order to model decimal addition and subtraction.  You will first practice modeling decimals with the blocks online (and on paper) and then perform addition and subtraction problems using the virtual base ten blocks from the website. 

The Task

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

The Process

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 
4. Save to Desktop and Print out
5. Use worksheet #2 along with the virtual base ten blocks to practice modeling decimal addition and subtraction
6. Complete worksheet #2
7.  In your notebook, make a table that looks the same as the table on worksheet #2 and practice at least 10 additional problems, 5 addition and 5 subtraction

Evaluation

The following rubric will be used to assess the webquest:

Conclusion

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

Credits & References

http://nlvm.usu.edu/en/nav/vlibrary.html
http://nlvm.usu.edu/en/nav/frames_asid_152_g_3_t_1.html
http://nlvm.usu.edu/en/nav/frames_asid_264_g_3_t_1.html