The number is written in scientific notation if it is written in two parts:

1) Just the digits (with the decimal point placed after the first digit), followed by

2) × 10 to a power that puts the decimal point where it should be (i.e. it shows how many places to move the decimal point).

40.3*10^-1 is not in scientific notation because the decimal point is not placed after the first digit

the scientific notion for 40.3*10^-1 = 4.03*10^0 or just 4.03.