Do we need separate rules to compute in decimal notation?

It is perplexing indeed that we continue to teach decimal fractions as if they were enti tic quite apart from common fraction. Typically, we first teach student to add, subtract, multiply, and divide with common fractions. Then in due course, as if decimal fraction (commonly called decimal) were a totally different concept from common fraction, we teach a new set of seemingly unrelated rules and regulations for moving the decimal point about...