To write $0.7852$ in scientific notation, we need to express it in the form $a \times 10^b$, where $1 \le a < 10$ and $b$ is an integer. Step 1: Move the decimal point to the right until the number is between $1$ and $10$. The number is $0.7852$. Moving the decimal point one place to the right gives $7.852$. Step 2: Determine the exponent of $10$. Since the decimal point was moved one place to the right, the exponent will be $-1$. Step 3: Write the number in scientific notation. $$0.7852 = 7.852 \times 10^{-1}$$ The number $0.7852$ in scientific notation is $\boxed{7.852 \times 10^{-1}}$. Last free one today — make it count tomorrow, or type /upgrade for unlimited.