Hmmm... I may be wrong, but I think that the number of significant figures you need to give is already given in the question itself.
88.375/1264.7= (all are 5 sig fig; answer in 5 sig fig)
234.6+89x6.8= (highest sig fig = 4; answer in 4 sig fig)
471-22.85= (highest sig fig = 4; answer in 4 sig fig)