Answer:
Scientific notation in science is used to simplify a math problem. For example:
938,472,500 is much harder than 9.384725 x 10 to the eighth power
Scientific notation is used to keep accuracy in measurements and to avoid writing out an outrageous amount of numbers (scientists can be somewhat lazy-maybe because their time is so valuable). For example, when doing calculations with numbers that are very large or very small such it is much easier to express using scientific notation. Planck's constant which is commonly used in many applications can either be expressed as 6.626x10^-34 Js (scientific notation), or as 0.0000000000000000000000000000000006626 Js (I might've missed or added a zero by mistake). Clearly scientific notation saves time and mistakes.
In many real world applications a range of values can cover a vast spectrum; a logarithmic scale is useful and employs scientific notation (common examples include the electromagnetic spectrum, pH scale, and the Richter magnitude scale).
Also using scientific notation allows for accuracy in a calculation; since only significant digits are kept and used in scientific notation meaningless (or invalid) numbers are disconsidered.