The answer will usually depend on the number of significant figures in the numbers from which there numbers were derived.
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
There are 5 significant figures in 70700 as the zeros are between and after the numbers.
3 significant figures.
It has five significant figures.
7 significant figures.
3 significant figures.
There are 5 significant figures.
3 significant figures.
2 significant figures.
Two significant figures.