Your multiplying by one tenth. That's basically saying reduce this fraction:
45.9/10
That's way smaller than 45.9.

 

You're not Multiplying by Zero, you're multiplying by .1, which is the same as 1/10th or .10, which is, as Lostalaskan said, 1/10th of 1. There are ten .10's in one, so .10 * 10 = 1. All fractions, for now atleast, will be out of 100.

You're looking for 1/10th of this item; 45.9.

45.9 * .1 = 4.59, or you could simply move the Decimal place over by one to the left. A is the right answer Good try though! I see how you made the mistake. Just remember that, in this case, you are multiplying by Fractions(or Decimals). A Fraction and a Decimal are the same, simply fractions are in the form 1/10th and decimals are in the form .10

Just wait till you get to Negative Numbers... xD

 

I didn't even notice that the result was 4.59 not 45.9. But the others are right. :b Likely I would have chose the same answer as you, simply because I didn't notice that tiny difference with the decimal point, lol

 

whut. I don't want to hear about mathematics during my break. I now eat meh donutz.

 

Reminds me of the time my math lesson said that 8 out of 10 questions answered correctly = 70% of the questions answered correctly....
>_>
<_<

But everyone else is right: Multiplying by a number less than 1 makes the number smaller.
And Ike is also right...If you thought that was hard, wait for negative numbers... That's when things get confusing.
Dividing them...
Then Multiplying...
Then Multiplying Negative Fractions....
Then Multiplying a Negative Fraction by a Positive Fraction then Dividing that by another Negative Fraction which is Divided by 9 to the Power of 13 which is Multiplied by XZ(13 * 47)

I'm just making math sound a lot harder than it really is now...
>.>