How to express a number in scientific notation
Write the number in decimal form. Only a digit other than 0 must be before the period, that is, it must be a real number between 1 and 10 (example: 1.5).
Count how many decimal places the point has moved.
Put this number of places as an exponent of 10. You must be careful when walking with the point: if the number decreases, the exponent will be positive (example: 10^5). If the number increases, the exponent will be negative (example: 10^-6).
In this case:
You have the number 2385.9. The point will move 3 decimals to the left. The number will decrease, so the exponent will be positive and the value of it is 3.
So it will be: 2.3859 × 10^3
Answer: 2.3859 × 10^3