determine the accuracy (i.e., the number of significant figures) of this number: 785000

Explanation:

Step1: Identify non-trailing significant digits

The non-trailing zeros are ambiguous here, but if we assume the number is written without a decimal point to indicate that the trailing zeros are not measured, the non-zero digits are significant. Digits: $7, 8, 5$ are non-zero.

Step2: Count significant figures

Count the definite significant digits. Count: $3$ (from 7, 8, 5) Note: If the number was written as $785000.$ (with a decimal), it would have 6 significant figures, but without the decimal, the trailing zeros are placeholders, not significant.

Answer:

3