- Minus 40 degrees or “40 below” is the only temperature that is the same in both Fahrenheit and Celsius
- It took chemists 40 attempts to develop the magical spray we know as WD-40. Stands for Water Displacement, 40th formula
- Forty is the maximum number of players a Major League Baseball team can sign to its roster at once.
- And, why is it that the standard American workweek is 40 hours?