Round the following numbers to the number of significant figures indicated: 345 (2 s. f.)
7850 (1 s. f.)
24.68 (3 s. f)
8.005 (3 s. f)
0.005758 (3 s. f)
1.25x1012 (2 s. f)

Explanation:

Above we have simply looked the condition that where we put decimal point that gives your needed answer after round off.

For example:

we have to make 2 s.f from 345 so we kept decimal after 3 and we rounded off to make 3.5 from 3.45

Hope you got it

that tool would be a compass

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.