Final answer:
Placeholder zeros are typically placed at the beginning of a number, known as leading zeros, and are not significant. They are used to locate the significant digits properly. Trailing zeros after a decimal point are significant, indicating precision in measurement.
Step-by-step explanation:
In identifying where placeholder zeros are typically placed, it is important to understand their role in numerical values. Placeholder zeros can serve a variety of purposes, varying their significance depending on their position.
Zeros placed at the beginning of a number, known as leading zeros, are not significant. They are solely there to put the significant digits in their correct position. For example, in the number 0.0009, the placeholder zeros before the 9 are not counted as significant figures.
On the other hand, trailing zeros that come after all non-zero digits in a number that includes a decimal point are deemed significant. For instance, in the number 15,450.0, the zero after the decimal point indicates a measurement and thus is significant. Conversely, right-end zeros in a whole number without a decimal point (e.g., 1300) may or may not be significant, leading to potential ambiguity without further context.