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
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.
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
Depending upon their level of skill, the line length assignments
can vary from 5 to 500 pixels at any increment of 5.
Students will need a list of the lines you want them to complete.
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.
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
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
- 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
- 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