How can the number of significant figures in such a number be made clear?

The number of significant figures in a measurement can be clarified by using scientific notation, which explicitly indicates the precision of the number. For example, writing 1.23 x 10^3 clearly shows three significant figures. Additionally, using decimal points or trailing zeros can also help; for instance, writing 1500 with a decimal point (1500.) indicates four significant figures, while 1500 without a point might imply only two. Lastly, employing parentheses or overlines can also denote specific significant figures in certain contexts.