BigNum Math

Chapter 1

Introduction

1.1 Multiple Precision Arithmetic

1.1.1 What Is Multiple Precision Arithmetic?

When we think of long-hand arithmetic such as addition or multiplication, we rarely consider the fact that we instinctively raise or lower the precision of the numbers we are dealing with. For example, in decimal we almost immediately can reason that 7 times 6 is 42. However, 42 has two digits of precision as opposed to the one digit we started with. Further multiplications of say 3 result in a larger precision result 126. In these few examples we have multiple precisions for the numbers we are working with. Despite the various levels of precision, a single subset¹ of algorithms can be designed to accommodate them.

By way of comparison, a ...