What is 45% in decimal?
A. 0.45
B. 0.0045
C. 45.00
D. 0.54

Hint: To convert any percentage into decimal, we need to follow the following steps:-
For example, let us take 23%. So, as we know that percent means per hundred, i.e. per 100, therefore, 23% = $\dfrac{23}{100}$ .
Now, we will shift the decimal towards the left because we have to divide 23 by hundred. Also, we will shift the decimal two places left. Now, to know how many places we need to shift the decimal, we need to look at the number of zero in the divisor. A hundred has only two zeros in it, so we shall shift the decimal to two places left. If the divisor would be thousand, i.e. 1000, then we need to shift the zero three places left.
So now, what we get is 0.23, which is the decimal form of 23%.

Complete Step-by-step answer:
For the solution, we will follow the same method, as explained in the hint.
So, we will have to convert 45% into fraction.
45%= $\dfrac{45}{100}$
As a hundred has two zeros in it, we need to shift the decimal two places left. After doing so, what we get is 0.45.
Therefore, the answer obtained is (a) 0.45.

Note: One must carefully look at the number of zeros behind the divisor. Also, the student must always shift the decimal towards the left while dividing any number by numbers such as 10, 100, 1000, 10000, etc.
If the student shifted the decimal towards right, then the answer that he will obtain will be wrong.