**Harold Camping calculates that the world will end on Friday, October 21, 2011. Mr. Camping and several like-minded persons shared the 2011 Ig Nobel Prize in mathematics**, for teaching the world to be careful when making mathematical assumptions and calculations.

**How does Harold Camping do math? **He shares his secrets in his mathematics text book: *The Perfect Harmony of the Numbers of the Hebrew Kings*. You can read the whole book online.) **Here are some tips from Mr. Camping’s book:**

- “There are no errors or real contradictions in the Bible.” [p. 3]
- God, an adept accountant, kept two sets of books. Knowing this, “we are enable [sic] to harmonize many of the Biblical citations that otherwise would remain impossible to understand”. [pp. 5-10. A helpful chart, showing two parallel entries, appears on page 8, and is reproduced here. Many other such charts appear later in the book.]
- “This study [of the two parallel sets of books] is very important in that it shows in a fresh way the total dependability of the Bible. It shows that without any questions the numbers and dates given in the Bible are entirely accurate. This fact gives further reassurance that every word in the Bible is absolutely trustworthy. [p. 10]
- “While at times the solution was very complex, we, nevertheless, have been able to harmonize Scripture with Scripture so that each and every verse became understandable.” [p. 80]

This little essay about Mr. Camping’s mathematics first appeared in the October issue of *mini-AIR*, several days prior to the (predicted) end of the world. In case your math is rustier than Mr. Camping’s, here’s a simple math primer, courtesy of Tom Lehrer: