How do you write 81.402 powers of ten?

To express 81.402 in powers of ten, you can write it in scientific notation. This involves moving the decimal point to create a number between 1 and 10. For 81.402, you would move the decimal point one place to the left, resulting in 8.1402, and since you moved it one position, you multiply by 10 raised to the power of 1. Thus, 81.402 can be written as ( 8.1402 \times 10^1 ).