Draw a map of the neighborhood around the school. Be sure to indicate the school's location on the map. Using the map, show the students the road directly in front of the school and the road behind the school. Unless one of the roads curves, they are parallel. Explain this concept to the students. Then, show the students one of the roads that crosses the parallel set of roads at a right angle. Explain to the students that these roads are perpendicular. Ask them to draw a map of their neighborhoods and to name other sets of parallel and perpendicular roads.
Tell the children to bring two small objects that could represent lines. These objects could include licorice, pencils, rulers, carrot sticks or pretzel sticks. Choose your own examples of lines and use them to show the students what parallel lines look like. Ask them to make their own parallel lines with their objects. Repeat the activity, but make perpendicular lines. The students will remember the difference between parallel and perpendicular better because their objects will serve as a visual mnemonic to illustrate the concepts.
Bring a book of fabric swatches or samples to the classroom. Show the students a few fabrics that have parallel lines. Then, send them on a hunt around the classroom to find other examples of parallel lines, such as the floorboards or the lines that books make in the bookcase. Then, show them a few pieces of fabric that have perpendicular lines. Ask them to look for perpendicular lines. Give a small prize to the student or team of students who find the most examples.
After explaining the concept of parallel and perpendicular lines to the students give them paper, pencils and rulers. Ask them to use the rulers to draw their own parallel and perpendicular lines. When the students have a grasp of the concepts, ask them to make patterns with parallel and perpendicular lines. For example, students could make a checkered pattern, or a pattern with large and small parallel lines. Give the student or group of students with the most creative patterns a small prize.