Subtraction: Montessori Style
November 29th, 2014
One of the (many) things I love about our kids’ Montessori school is that they allow a great deal of freedom while also making sure the kids are learning what they need to.
Case in point: last year, Miss Mouse was all about reading. All About Reading. She had mastered the basics in the spring of 2013 and went into Year 2 of the three-year Montessori cycle hungry to read everything she could get her hands on.
This year, she still loves books, but her teachers have also encouraged her to turn her attention to math and now she’s hooked. She chatters cheerfully about her addition cards and bead chains and other things incomprehensible to an outsider (like me).
The hallmark of Montessori math is that it is taught using concrete materials. The students use beads and other counters to learn place value and relationships between numbers. For example, early in the year, Miss Mouse learned about even and odd numbers. When she talked about them, she referred to numbers “with friends” and numbers “without friends.” I was completely baffled, but when I threw numbers at her, she could correctly identify them as even or odd every time.
After talking to her teacher, I learned to decode this strange language. Odd numbers could be represented by two bead chains of unequal lengths (one had an extra bead – the “friend”) while even numbers were represented by two bead chains of equal length (no extra “friend” bead). When considering each number I mentioned to her, Miss Mouse would picture the chains in her head before responding.
A few weeks ago, she started learning subtraction and quickly started coming home with sheets of paper showing four digit subtraction problems. I’ll confess: I was impressed. And also curious. How did a Montessori student approach subtraction?
I had Miss Mouse walk me through the process at a recent open house. It’s pretty cool, as you’ll see in the video.
Because she’s just starting out, it’s time consuming. It’s a very methodical process. But she is training her brain to have a concrete understanding of mathematical concepts.
That training will stay with her. Last year, the school hosted a panel discussion of former students who are now in college. One thing many of them mentioned was that they continue to “see” math problems in ways that their peers who did not have a Montessori education did not.