In the age of an object measured at 4,540,000,000 years, what can be said about the zeros?

When considering the measurement of an age like 4,540,000,000 years, it's important to understand the role of zeros in significant figures. In this specific scenario, the zeros that appear after the digits (4, 5, and 4) are not counted as significant figures since they serve merely as placeholders.

The significant figures of a number are those digits that contribute to its precision. In this case, only the digits 4, 5, and 4 are significant, as they indicate the measured value directly. The zeros that come before the first non-zero digit are considered leading zeros and are not significant, while those at the end of a whole number without a decimal point serve as placeholders and are not counted as significant figures in the context of this number.

Thus, when determining the number of significant figures in 4,540,000,000 years, we count the three non-zero digits (4, 5, and 4), and therefore, we conclude that the zeros are not significant in this case.