The number "4.54 × 10^-3" is expressed in scientific notation, which is a way to represent very small or very large numbers. In this case, the "-3" indicates that the decimal point should be moved three places to the left. Therefore, "4.54 × 10^-3" is equivalent to 0.00454. This format is commonly used in fields like science, engineering, and mathematics to simplify calculations and make it easier to read and write numbers that are either very small or very large. For example, it can represent measurements like millimeters or concentrations in chemistry.