Developmental Dyscalculia and Brain Abnormalities
Most diagnostic criteria use the term developmental dyscalculia (DD) to describe moderate to extreme difficulties in fluent numerical calculations that cannot be attributable to sensory difficulties, low IQ or educational deprivation. Numbers do not seem to be meaningful for dyscalculics—at least, not meaningful in the way that they are for typically developing learners. They do not intuitively grasp the size of a number and its value relative to other numbers. Common indicators of DD:
- Carrying out simple number comparison and addition tasks by counting, often using fingers, well beyond the age when it is normal
- Finding approximate estimation tasks difficult
- To say which is the larger of two playing cards showing 5 and 8, they count all the symbols on each card.
- To place a playing card of 8 in sequence between a 3 and a 9, they count up spaces between the two to identify where the 8 should be placed.
- To count down from 10, they count up from 1 to 10, then 1 to 9, etc.
- To count up from 70 in tens, they say “70, 80, 90, 100, 200, 300…”