ADHD Brain and Sticky Notes
There’s a great post entitled, “Sticky Note Memory,” by ADHD Inside and Out. It hits home with a lot of us who parent or work with children who have attention deficit disorder.  It equates “working memory” to a sticky note stuck to a wall in your brain.  Normal brains can hold many sticky notes, but ADHD brains can hold only 2 or 3 sticky notes at a time making it difficult for them to plan, do and complete boring tasks. 
It’s a great explanation of why a student with ADHD can have working memory issues:
Children who have memory difficulties should work on “storing” the information more efficiently in their memory and reducing the number of “sticky notes” they need to store.  In other words, break down the information you are asking your child/student to remember into smaller, easier to store chunks and work on memory strategies to improve recall of information.