The functions we're using return text strings. To make Excel convert the text
to numbers, we need to use an arithmetic operator. You'll see, at various
times, we multiply the result by 1 OR we'll preceed the result with -- (two
minus signs which offset each other). Also, we only do that if the expected
result will be:
Numeric text: to return a number
or
Boolean (true/false): to convert TRUE to 1, FALSE to 0 (zero)

Otherwise, an error is returned. (There is no such thing as negative "Tree")

Does that help?
--
Regards,
Ron