Alexic Acalculia
In pure alexia, that is not associated with agraphia, acalculia is limited to reading numbers. This is to be expected considering that those with alexia lose the ability to read written words and sentences. Digit-by-digit reading, however, is still observed but may be done asymmetrically. Therefore, these individuals will start reading a number one digit at a time but omit later digits. It is easier for them to read earlier digits then the last ones (eg, 395 is read 39).
Furthermore, in central alexia there is an inability to read written numbers and numerical signs. Mental calculation, however seems to be better. This suggests that these individuals still posses the knowledge to perform mathematical problems but the inability to read provides a large obstacle. Overall the reading and writing difficulties in addition to computational difficulties points toward severe acalculia.
(Ardila, 2008)