# Innovative Subtraction Strips, Alison’s Montessori

Mathematics, 5+

The Subtraction Strips set has been designed by Dr. Daniels Jutras, director of the Canadian Montessori Teacher Education Institute, as an alternative material for the Montessori Subtraction Strip Board. Alison’s Montessori is manufacturing this exclusive Montessori math material to respond to diverse learners in Montessori classrooms.

The Subtraction Strips set consists of a base with slots that host 17 red strips representing the subtrahend, a quantity that is subtracted from a larger quantity. In front of the tray is a printed numbered strip bordered by 2 horizontal grooves, which are used to slide a wood bar to the right and isolate the minuend, the quantity from which another quantity is subtracted.

The Subtraction Strips set does not replace the classic Subtraction Strip Board, it aims to facilitate the introduction to subtraction. In Montessori, other materials sensorially acquaint children with the concept of subtraction such as the Golden Bead Bank Game, Table Top Number Rods and Subtraction Snake Game. However, the Subtraction Strips prepares children for the work of memorization and for abstract learning. You will find below instructions on how to use the Subtraction Strips to solve prepared equations.

## How to Use the Material

Bead Materials Subtraction Activity, children will be prepared for memorization work on subtraction facts. This is an individual presentation. Invite a child to the shelf where the material is located. The child will be able to carry the material at once. Use a table preferably so that the numbers on the upright strips are clearly apparent to her.

First, select an equation from prepared materials such as the Subtraction Tables. In my example below, the equation is 12 – 9 = ___. If the subtrahend is 12, slide the sliding strip along the grooves, over the strip of numbers, until all the numbers passed 12 are covered. Now the child can see that we are going to subtract a small quantity from this larger quantity. Select the red strip “9.”

You can place the red strip (9) in the groove above the strip of numbers, to the far right, so that the minuend is contrasted with the subtrahend (12). You can superpose the red strip to cover all the quantity that has been taken away.

Now remove your hand and point at number 9. Follow the direction in which the arrow is pointing with a slow movement. The difference appears on the left side of the red strip.

Record the answer on a worksheet or a booklet. The Subtraction Strips set requires fewer steps to access and understand the concept of subtraction. It may help younger, struggling, or reluctant learners to approach the material and keep on practicing subtraction facts. You may use the Subtraction Strip Board once a child is comfortable with the concept.

You can be certain that more curious hands and eyes will approach the subtraction fact memorization using the Subtraction Strips set! The Subtraction Tables from Alison’s Montessori contain 18 sheets of exercises to accompany the Subtraction Strip Board. They may be used with the Subtraction Strips as well.

Many people are satisfied with this novelty. I believe in its potential so much that I ordered it on the day I discovered it. I am happy to share it with you and hope your five-year-old will develop a strong arithmetic foundation using respectful materials that progressively lead them from concrete learning to abstract learning.