Answer
The student did not move the decimal back the correct number of places. Instead of writing $1.88\times10^{-5}=0.00188$, the student should have written $1.88\times10^{-5}=0.0000188$.
Work Step by Step
To convert a number in scientific notation to a number in standard notation, we must move the decimal point to the left or right by the exponent of $10$ in the scientific notation. If the exponent is positive, we move the decimal right. If the exponent is negative, we move the decimal left.
The student was trying to convert $1.88\times10^{-5}$ to standard notation. Since the exponent of $10$ is $-5$, we move the decimal point $5$ places to the left, giving us $0.0000188$, not $0.00188$.
