Here's how to convert Fahrenheit to Celsius:

Formula:

Celsius = (Fahrenheit - 32) * 5 / 9

Calculation:

* Celsius = (42 - 32) * 5 / 9

* Celsius = 10 * 5 / 9

* Celsius = 5.56 (approximately)

Therefore, 42 degrees Fahrenheit is approximately 5.56 degrees Celsius.