Final answer:
The square root of a decimal number that is a perfect square will have a finite number of decimal places, as a perfect square always has an integer or a rational square root that can be expressed as a finite decimal.
Step-by-step explanation:
If a decimal with a finite number of decimal places is a perfect square, its square root will also have a finite number of decimal places, which is option A). This is because when you take the square root of a perfect square, the result is an integer or a rational number that can be expressed as a finite decimal. This concept is an aspect of number theory within mathematics where exact numbers, such as those obtained from counting objects, are considered to have infinitely many significant figures by definition.
However, in operations like addition and subtraction, significant figures do not necessarily play a role in determining the number of decimal places in the result. Instead, the answer will have the same number of decimal places as the number with the least number of decimal places in the original numbers. Meanwhile, in multiplication and division, the answer is rounded to the same number of significant figures as the least precise number involved in the calculation.