Introduction to Perimeter and Area

This post provides a conceptual approach to understanding perimeter and area.


Students are prompted to build an rectangular animal pen for some farm animals. The number of fences represents the perimeter. The number of squared segments of grass inside the pen represents the area.

Google Jamboard

The slides are presented below. This video shows how the manipulatives work.

Access to Jamboard.

Here is a link to the Jamboard. Need to make a copy to use it.

Customized Number Lines for Handouts

Per request, I created a short video showing how I create customized number lines on WORD. This post also includes a link to a WORD document with 3 customized number lines: time, money with negatives, and miles.

Elapsed time

The image below is from a post on elapsed time. I wanted to create different time scales to match clocks I could create on

The Video

In the video I show how I created the time number line. In the top image below, you can see the table highlighted. I then show how I copy and paste the number line and then edit to create units with money, with negatives.

Here is a screenshot of the video. You can see the number line in an early stage of development. Below the image is a link the video.

Link to video


Below is an image of the three customized number lines. Here is a link to the handout, which is in WORD format to allow you to revise to suit your work with students.

If you find this helpful, please consider making a small donation to a fund to build an accessible playground at a camp site for individuals with disabilities.

Fractional Units of Ruler – Instructional Strategy

The fractional units of a ruler and measuring fractional lengths can be tricky, especially for students with processing, working memory, or visual related disabilities. For the students I have helped, here is the approach I have used.

I relate the fractional marks and counting them to walking across a set of stepping stones. This ties into their prior knowledge and allows for a hands on activity of moving the girl across the stones.

I present the girl and the stepping stones as the setting. Then I explain that she will take steps to walk across the stepping stones to the other side. Students count stones to determine steps. Below is an image of a Jamboard that allows for moving the girl.

Below is an image of a handout I use to address this prior knoweldge.