Ten wooden rods painted red, different in one dimension: length. The shortest rod is 10 cm long and each succeeding rod is 10cm longer; the longest rod is 100 cm (1 meter). The width and height of the rods is 2.5 cm by 2.5cm.
- Invite the child to the lesson. Ask the child to watch.
- Starting with the shortest rod, carefully pick up the rod with both hands and hold it straight up in the air, parallel with the body.
- Place the rod down with both hands on a random spot on the rug.
- Continue this process one rod at a time while inviting the child to help by doing the same.
- Once all the rods are placed randomly on the rug, look for the longest rod and pick it up with both hands, place it in the left back corner of the rug so that it touches the edges of the rug.
- Once the rod is placed, glaze over the rod with your dominant hand to experience its length.
- Find the next longest rod and once again pick it up with both hands and place it in front of the previous rod in the left corner, aligning the left side. Glaze over the rod, gaze the left side of the rods as well to make sure they are even and aligned.
- Continue this process by progressively picking up the next longest rod and placing it in the left corner, aligned with the previous rods.
- Once the red rods are organized and complete, randomize the rods and let the child perform the exercise.
- To clean up this material, be sure to go in reverse order of taking the rods off the shelf. Take the longest rod back first, and progressively take rods back one at a time until the last rod to take back is the shortest.
Same as presentation.
Short, long, shorter, longer, shortest, longest.
Grading at a Distance: Place two rugs on the floor far apart from one another. Place all the rods on one rug, and request the child to organize the red rods on the other distant rug by asking him to bring the longest rod, and then the slightly shorter rod, and so on.
Control of Error
Lies within child, visual as rods will go from shortest to longest.
Visual discrimination of dimension.
Refinement of voluntary movement, preparation for the mathematical mind, muscular memory of length.
3 ½ – 4
The shortest rod is a measure of difference between any two successive rods. Goal is to build intellect and make discoveries. Rods vary also in weight, but that isn’t visually apparent.