To sign Math, form flat ASL letter M sign with both hands. Then pivot them such that the fingertips of both hands face each other. Swing both 'M' hands towards each other and have both 'M's meet in the middle. Swing them in and out, as if you are imitating cogs moving in the machine called your brain, as you are trying to figure out a mathematical problem.
Teach your toddler the math sign when you are introducing them to number blocks or puzzle pieces, or when they are already beginning simple math exercises in preschool.
Teach your toddler this sign in conjunction with the numbers and counting flash cards.