The red rods are a sensorial material in the Children’s House classroom, consisting of ten rods that gradually increase in size by 10-centimeter increments, starting at 10 centimeters going up to 100 centimeters. The red rods are one of the first sensorial materials a child is introduced to, along with the knobbed cylinders, pink tower, and brown stairs.
The child will first use the red rods by placing them, one by one, on a work mat, in random order. He will then place them on a second mat, one at a time, arranging them from longest to shortest, aligning the left edges of the rods. The rods are self-correcting, in that, if the child does not place them from longest to shortest, he will quickly observe that the “stairs” he has created have not aligned properly.
There are several extensions to this activity. For example, the child can combine two rods of varying lengths to equal the length of another rod. (Wonderful for developing a mathematical mind!) He can also build a maze out of the rods by placing the rods at 90-degree angles, building from smallest to largest. The child will also use these rods in combination with the number rods to do several math extensions!
As with all materials, there are both direct and indirect purposes. The red rods aid in developing the child’s visual discrimination and muscular memory of length while indirectly preparing the child for mathematics.
We will use these terms frequently while exploring the Montessori materials, so let’s dig into a little more about what those mean in relation to the child’s development.
What is visual discrimination?
Visual discrimination is the ability to discern the differences between different objects. It involves noticing details and comparing and contrasting objects (size, color, orientation, etc.). While this is something that most children naturally develop, it is beneficial for future academics to introduce young children to activities that help them to fully develop and refine their visual discrimination skills.
Why is visual discrimination important for academics?
Visual discrimination is necessary for a child to recognize the difference between the letter “a” and the letter “b”. It is necessary for a child to look at a pile of 3 marbles and discern that it less than the pile of 6 marbles (and later, recognize that is half of the quantity). If a young child has poor visual discrimination, they may struggle with matching games and puzzles, or may confuse details. An older child may confuse letters (and/or numbers) that look similar (s / z, 3/E, b/d), lose their spot while reading, have trouble copying words accurately, have trouble picking out important details, trouble judging distance and height, etc.
What is muscle memory and why is it important?
Muscle memory involves “consolidating a specific motor task into memory through repetition.” It involves physical motor tasks as well as mental tasks. Muscle memory is an important part of recognizing patterns and is built through repetition. “As movements are repeated over time, the brain creates a long-term muscle memory for that task, eventually allowing it to be performed with little to no conscious effort.” (Source.) Muscle memory can involve something like playing an instrument, typing on the computer, or even memorizing the times tables. Building these connections benefit the child’s learning, as they are the building blocks upon which more and more complex connections are made.
Developing visual discrimination at home
To aid in developing visual discrimination at home, you can provide your child with the following activities:
- Sorting activities (sorting different shaped pasta, cutlery, colored pom poms, types of beans, types of coins, etc.)
- Categorizing activities (categorizing types of leaves, categorizing different objects by shape or color or size)
- Matching activities (matching socks, matching/memory games, shadow matching cards, the game “Spot It”, )
- Asking your child for detailed descriptions of events, objects, people, etc.
- Playing the “opposite game”. (I say, “Cold,” you say “Hot”.)
- Memory game: put a tray of assorted objects in front of your child for a few seconds, then cover it and ask your child to recall what was on the tray


