In Excel 2010 there's an explanation of what a circular reference is on page 243. It states you'll get an error message if you type such a formula. However, I get only zeros. I googled this issue and learn Excel does indeed give you a zero if you create a circular reference. Is this a mistake in the book?
which Excel 2010 book is it specifically? We have a few out: Step by Step, Inside Out, Plain and Simple, etc.
I can search the errata for you and determine if it's a known issue that's been addressed by the author or not.
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