Answer:
A 1.8 × 10⁸
D 8.0 × 10⁶
B 1.2 × 10⁶
C 2.4 × 10²
Explanation:
the scientific notation is nothing else than 10 to the power of an exponent multiplied by the first number.
that exponent of 10 makes the main decision about the size. the higher the bigger.
if the exponents are equal, then the first number decides.
10⁸ is the largest number compared to the others.
then 10⁶, then 10².
but beware of tricksters among teachers and testers.
what I just explained works without any additional steps only if the scientific notation is truly followed.
that means the first number has exactly 1 position left of the decimal point, and it is not 0.
but anybody could write something like
3126.9 × 10⁴
it is not scientific notation, but it is a valid number in general.
so, is
3126.9 × 10⁴
smaller or larger than A, B, C, D ?
we get the answer by converting the general number into scientific notation, and THEN we compare :
3126.9 × 10⁴ = (3.1269 × 10³) × 10⁴ = 3.1269 × 10⁷
aha !
it is smaller than A but larger than D and B.
and yes, of course, larger than C.