Here's how to convert Fahrenheit to Celsius:

Formula:

Celsius = (Fahrenheit - 32) * 5/9

Calculation:

1. Subtract 32 from the Fahrenheit temperature: 70 - 32 = 38

2. Multiply the result by 5/9: 38 * 5/9 = 21.11 (approximately)

Therefore, a room temperature of 70 degrees Fahrenheit is approximately 21.11 degrees Celsius.