Storage and/or automatic retrieval of the basic facts of addition from the long-term memory seems to be impaired in children with ADHD presenting arithmetical difficulties. The present study was carried out to evaluate the effectiveness of an educational intervention model designed to teach basic facts of addition as a means of advancing from…

Fifty Brazilian children aged seven-13 were individually given addition and subtraction exercises. Counting was the preferred procedure, with use of school-taught algorithms limited. Some children decomposed numbers into tens and units and then worked at both levels. They rarely referred to previous results when doing related exercises. (MNS)

A 14-year-old Brazilian boy in the fourth grade was given 170 problems orally, each asking for the sum of 2 2-digit numbers. Responses indicated he had invented his own algorithm for addition, similar to the school one, based largely on his experiences with money. (Contains 13 references.) (JAF)