This page describes the contents of the file multiplication.xls, which you can download below. The file contains two macros that do multiplication. This is much simpler than division and less interesting.

Multiplication - two versions

Version 1 multiplies a big number by a small number. It reads the big number into a VBA array before beginning the calculation. As it reads the number, it checks the input. Each digit of the big number goes into a separate element of the array. This version can handle decimals in both the big number and the answer. The small number must be an integer.

Version 2 multiplies a big number by another big number. Like version 1, it reads the big numbers into VBA arrays before beginning the calculation and does identical validation checks. Both input numbers can include decimals.

Both versions use a simple, schoolboy approach to long multiplication.

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