0.0025 in scientific notation
Understand the Problem
The question is asking to convert the decimal number 0.0025 into scientific notation, which involves expressing it as a product of a number between 1 and 10 and a power of ten.
Answer
$2.5 \times 10^{3}$
Answer for screen readers
The scientific notation for 0.0025 is $2.5 \times 10^{3}$.
Steps to Solve

Identify the Base Number To convert the decimal number 0.0025 into scientific notation, we first need to express it as a number between 1 and 10. We can do this by moving the decimal point.
For 0.0025, we move the decimal point 3 places to the right, which gives us 2.5. 
Determine the Power of Ten Each time we move the decimal point to the right, we are effectively dividing by 10. Moving it 3 places means we are dividing by $10^3$. To express this in scientific notation, we need to account for this by using a negative exponent, which indicates a division.
So, we express this as:
$$ 0.0025 = 2.5 \times 10^{3} $$ 
Final Scientific Notation The final expression we obtain is therefore the scientific notation for 0.0025:
$$ 2.5 \times 10^{3} $$
The scientific notation for 0.0025 is $2.5 \times 10^{3}$.
More Information
In scientific notation, the exponent indicates how many places the decimal point has moved. A negative exponent shows the number is less than 1.
Tips
 A common mistake is to forget to use a negative exponent when moving the decimal point to the right. Always remember that moving right corresponds to a negative exponent.