Ruler:

Lesson Description:

Ruler is a great way to reinforce the concepts taught in early geometry. In the activity the students use the computer graphics tools in Canvastic to create lines of certain lengths. It can be adapted to whatever levels of geometric angles have been taught or need to be practiced. It can be a short one session activity or can span multiple days as an on-going practice activity. It could also be used as an assessment of that knowledge. Grades 3-4. Example below.

Implementation Steps:

Introduce the Object tools if necessary. Pay particular attention to the concept of editing with the Pointer tool and Choices palette as small adjustments to a geometric figure are helpful. The Line tool will be the main one used in this activity. See the Canvastic documentation for an explanation of the these tools.

Have the students open the Ruler-Pixels.cdc template file. Click here to download a copy. This file has a ruler in the background layer of the document where it cannot be easily erased or deleted. There are some printed instructions as well that read:

This ruler measures pixels. Pixels are the smallest dots that can be shown on the computer's monitor. The ruler shows a total distance of 500 pixels from end to end.
Questions:
1. How many pixels are there between the largest marks?
2. How many between the middle sized marks?
3.How many between the smallest marks?
Follow your teacher's directions to create some lines with the line tool that are certain lengths.

Have the students use the Line tool to explore how to draw lines of different lengths. Have them use the Pointer tool to move their lines away from the protractor.

Then have the students use the Line tool to draw lines of lengths that you assign. You can have them label them completely with the measurements. Remind them that the units they are using are "pixels". You can make the assignment as detailed as you wish. You may want to have them use certain colors for certain lines to make assessment easier.

Depending upon their level of skill, the line length assignments can vary from 5 to 500 pixels at any increment of 5.

Preparation Notes:

Students will need a list of the lines you want them to complete.

Student Prerequisites:

Students should probably use the Object vs. the Paint tools for this activity. It can be done with the Paint tools but the objects will make a better project. So, if they haven't used them, the object tools should be introduced first.

Assessment:

Resources:

• The Math Forum - Geometry - http://mathforum.org/library/drmath/sets/elem_geom.html
• Example
• Ruler-Pixels template file

Standards Addressed:

ISTE NETS Technology Standards: Grades 3-5 Performance indicator(s):

1. Use keyboards and other common input and output devices (including adaptive devices when necessary) efficiently and effectively.

5. Use technology tools (e.g., multimedia authoring, presentation, Web tools, digital cameras, scanners) for individual and collaborative writing, communication, and publishing activities to create knowledge products for audiences inside and outside the classroom.

ISTE NETS Technology Standards: Grades 6-8 Performance indicator(s):

5. Apply productivity/multimedia tools and peripherals to support personal productivity, group collaboration, and learning throughout the curriculum.

6. Design, develop, publish, and present products (e.g., Web pages, videotapes) using technology resources that demonstrate and communicate curriculum concepts to audiences inside and outside the classroom.

NCTM - National Council of Teachers of Mathematics - Standards::

Geometry Standard for Grades 3–5: Use visualization, spatial reasoning, and geometric modeling to solve problems

• build and draw geometric objects;
• create and describe mental images of objects, patterns, and paths;
• identify and build a three-dimensional object from two-dimensional representations of that object;
• identify and draw a two-dimensional representation of a three-dimensional object;
• use geometric models to solve problems in other areas of mathematics, such as number and measurement;
• recognize geometric ideas and relationships and apply them to other disciplines and to problems that arise in the classroom or in everyday life.

Geometry Standard for Grades 6-8: Use visualization, spatial reasoning, and geometric modeling to solve problems

• draw geometric objects with specified properties, such as side lengths or angle measures;
• recognize and apply geometric ideas and relationships in areas outside the mathematics classroom, such as art, science, and everyday life.