In the packing method, all numbers are first converted to integers by multiplying the original number with 10**IPREC, a user specified quantity. They are then truncated at the decimal point. The minimum offset to make all numbers positive is then found and added to each value. The optimum packing factor is then determined. This factor is chosen so that the minimum number of words are used after packing. The data is then packed, except for those words which cannot be stored with the chosen packing factor, which are stored in 32 bit words. Here again 3 extra words are used to keep useful information, as follows: