VAT CALCULATOR VERSION 1 (1K ZX81)
from ZX Computing 2, August/September 1982, page 110

This is a 1K program which will work out the price-plus-VAT and price-less-VAT
of any amount entered in pounds (within the limits of the numbers the ZX81 can
handle of course). The rate of VAT is fixed at 1 5% by the formulae in lines 60
and 90 and these must be changed for any other rate of VAT. The figures
displayed are rounded off to the nearest penny and justified to two places of
decimal with zeros added as are required by the subroutine starting at line 150.

The program may be of use to shoppers who wish to display VAT inclusive and VAT
exclusive. You should know whether the original amount you enter includes or
excludes VAT, and choose the figure you require off the screen - both figures
are displayed to prevent the user having to specify which answer is wanted.
This was found to be a far better method. When the ZX81 asks for an input,
enter the figure in pounds, even if it is less than 1.00.

[The program contains a bug in line 70, which should also print an '=' sign.]
