Type (A) is a very special type of procedure. One may object to the use
of the word ‘procedure’ when the child’s reasoning is not disclosed.Yet, an
(A)-procedure does satisfy the conditions formulated in the Introduction.
It is an act of transforming the expression and has certain characteristic
features. During the interviews the author sometimes had doubts how to
classify certain procedures, but this never happened in the case of (A)-
procedures. It should be emphasized that the crucial criterion was the
behaviour and attitude of the child, not only specific words used during
the interview; consequently, it is difficult to present it faithfully in print.
Type (A) was noted only in Grade 8, only in the case of best students, and
only when operations were really easy for them. It never occurred when
operations on negative numbers were involved.