Teaching Math to a classroom with students with developmental disabilities can be a challenging task. The cognitive functioning level most often varies from student to student.
I wrote this subtraction song in hopes that the lowest functioning students would grasp the concept of subtraction by the fact that subtraction means "take away". This can be taught in numerous ways. Real visuals are most helpful and the student can be taught to "take away" something from a box or bin.
All students enjoy playing subtraction with some sort of reward (subtracting with skittles, m&m's, crackers,etc), and each student takes a turning "taking away" a snack from a bowl. This makes the basic lesson of "taking away" (aka subtraction), fun and motivating. Later, students can be assigned certain numbers of things to "take away", and the teacher can facilitate counting what's left.
Stay tuned for more songs to help teach Math!