This is a very enjoyable read. The premise it to point out maths errors in an attempt to learn from others mistakes.

Some highlights:

• Pepsi jet engine mistake. Pepsi promo offered to buy you a jumbo jet if you got enough coupons. Someone did the maths and bought the coupons for a discounted Jet. Pepsi complained, took them to court and sadly Pepsi won in court. Alas.
• Engineering error led to the saying: "measure sea level twice, build a 225-meter bridge over it once."
• Fence post / off by one issues. There are 3 fence posts for 2 fence panels. Often the surrounding or starting index is missed.
• The authors friends celebrated in a pub as Unix time hit 1234567890
• Donald Trump tried to argue medical insurance of 3.49% rounded down was in compliance with legislation of "upto 3%". He lost in court. Hurray.
• 19.6% of gene research has autocorrected excel mistakes on gene names like MAR-5 (converted incorrectly to a date)
• Swiss hole argument of mistakes. People make mistakes. Make sure there aren't holes all the way down so people mistakes can be caught.