ABSTRACT
For efficient application, approximate solution techniques require the use of a digital computer. This chapter briefly investigates the manner in which numbers are stored in, and manipulated by digital computers. Such an investigation brings to light certain sources of error that plague the numerical implementation and use of all approximate solution techniques. Digital computers store information either as characters (text number representation) or as numbers (binary number representation). Characters consist of the letters of the alphabet, in both upper and lower case, numbers, and special characters (for example, punctuation symbols). Combinations of characters form text strings. The chapter focuses on the storage and manipulation of numbers, for further information on characters and character strings. Digital computers store numbers not with infinite precision but rather in some approximation that can be contained in a fixed number of bits. Such binary numbers fall into one of three types: bytes, integers or fixed-point numbers, and floating-point numbers.
