This study attempted the design of a program for gifted children based on De Morgan\'s
view of the development of algebraic and negative numbers. De Morgan\'s view of the
development of algebra makes the following distinctions: universal arithmetic, symbolic algebra,
and significant algebra. The important feature of De Morgan\'s view of the development of
algebra is that symbolic calculus, which consists of symbol systems without symbol meaning,
is acquired; then, as extended meanings are furnished to symbols, symbolic calculus becomes
logical and significant calculus is developed. In De Morgan\'s approach, the mathematical
conceptions of students must be formulated progressively. To examine the feasibility of De
Morgan\'s approach, a pilot study was designed: a program for gifted children, exploring
impossible subtraction, investigating the rule for impossible subtractions, and constructing the
significance of impossible subtraction in succession.