One of the more effective methods to demonstrate adding positive and negative numbers involved using semi-transparent colored plastic chips on an overhead projector (younger folks can ask a seasoned educator about this once ubiquitous device). Blue chips represented positive numbers, while yellow chips stood for negatives. When you added a positive number with a negative number you would put the chips on the overhead projector and then pair up the positives with the negatives by placing the blue chips on top of the yellow chips. Since they were see through, a blue chip and a yellow chip would look green, which indicated the positive and negative cancelling each other out. Whichever color had chips left over would be added up to give the final answers to the addition problem.
This activity lends itself very well for being converted over to a digital format, and a perfect tool for this is Google Drawings. To illustrate this I have created a Google Drawing template that you and your students can use to teach or practice adding integers.
See below for a short video demonstrating how to use the template, as well as a link to access the template.
Note: This Google Drawing template is view only. You will need to make your own copy of the file to use it. Simply click “File” then “Make a copy” to get your own editable copy of the file.
- Template - Adding Integers with Google Drawings - Google Drawing link
With this tool your students will be positive about negatives!
If you found this information useful, you may also like some of my other Google Drawing ideas for math here:
- Teaching Math with Google Drawings - help guide and training video: http://www.controlaltachieve.com/p/resources-google-drawings.html