Larry made a mistake when he calculated 0.4% as a fraction.
To convert a percentage to a fraction, we divide the percentage by 100. In this case, 0.4% divided by 100 is equal to 0.004. However, Larry incorrectly calculated it as 10.
The correct fraction that represents 0.4% is 0.004, not 10. It is important to be careful when converting percentages to fractions to ensure accuracy.