Leslie, my VPD boy has issues with memorising too but he can manage anything set to music. It's his outlet. We used a programmed called Times Alive! for multiplication memorization which REALLY well. To this day if he has a brain fog moment I can just mention a character from the story & he can recall all the facts to put together what he needs. Yes, we often sound REALLY weird during math time when a child asks for help with some simplistic problem & I say weird things like, "Snowman" or "Flag" but it worked for us. Not sure if it would be helpful for you or not..