From: Man. on
Math Difficulties People with dyslexia are often gifted in math. Their
three-dimensional visualization skills help them "see" math concepts
more quickly and clearly than non-dyslexic people. Unfortunately,
difficulties in directionality, rote memorization, reading, and
sequencing can make the following math tasks so difficult that their
math gifts are never discovered.

Memorizing addition and subtraction facts

Memorizing multiplication tables

Remembering the sequence of steps in long division

Reading word problems

Copying an answer from one spot to a different spot

Starting a math problem on the wrong side

Showing their work

They often "see" math in their head, so showing their work in almost
impossible.

Doing math rapidly

They often excel at higher levels of math, such as algebra, geometry,
and calculus—if they have a teacher who works around the math problems
caused by their dyslexia.

http://www.dys-add.com/symptoms.html