Use different colors of ink or markers when talking about different functions.
"When we used calculators my student with Aspergers would have to know the entire process from beginning to end before he would start, and the other students needed the instructions in parts.
I would write the math problem on the board using different colored ink when talking about functions of the calculator, so the AS student understood the difference, and it worked.” Alice McDonough, a teacher in Butte, Montana
Julie Coates suggests that this technique would also be beneficial for many other kinds of learners. Ms. McDonough made her comment during Coates' online course on Students with Aspergers.