What is the value of 4/10 - 3/6

Pls , the question is in the picture!

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.

Ineeeeed this is due tomorrow and i dont know the answer can you find all the exponents