Hannah is asked to convert the number 0.00000305 to scientific notation. Her answer is 3.05 x 106. Which statement best describes her answer?

Hanna converted the number:

0.00000305

to:

3.05x10^6.

Now, when we have:

Ax10^n

This will "move" the value of A n times to the left, adding zeros when the decimals of A run over.

if we have

Ax10^-n

This will move A n times to the right.

Then the number:

3.05x10^6 = 3050000

This is clearly not the number that Hannah wanted to write.

The problem is that the exponent should be negative, if we have instead:

3.05x10^-6

We move our number 6 times to the right, adding zeros when necessary.

3.05x10^-6 = 0.00000305.

So Hannah is incorrect, she should wrote 0.00000305 = 3.05x10^-6