Because it allows people to write otherwise unreasonably long numbers in a much smaller space, and still be able to understand them, and calculate with them.
Scientific notation is a convenient tool for writing very large or very small numbers.
It is 8.9*10^-5 in scientific notation
It is "(scientific notation)".
This number in scientific notation is 9.8x10-5.
It is: 2.7*10^0 in scientific notation
The scientific notation for 89,450 is: 8.945 × 104
9.32 x 105 already is in scientific notation.9.32 x 105 already is in scientific notation.9.32 x 105 already is in scientific notation.9.32 x 105 already is in scientific notation.
A good reason to learn scientific notation.
There is no true opposite of scientific notation, but the closest answer is Standard Notation.
510 in scientific notation is 5.1x102.
It can be written (in scientific notation) as 8.76x108.
3.0054E-2 is the scientific notation.