Final answer:
The number 8.1E + 10 can be expressed in scientific notation as 8.1 × 10^10.
Step-by-step explanation:
The calculator display shows 8.1E + 10, which is in scientific notation. In scientific notation, the number is represented as a decimal number between 1 and 10, multiplied by 10 raised to a certain power. In this case, the decimal number is 8.1, and the power of 10 is 10.
To express this number in scientific notation, we write it as 8.1 × 10^10.
Therefore, the correct answer is (a) 810,000,000,000.