560.589 - 23.47 is hmm 537.119 <---- 6 significant digits
alrite... looks good, however, when it comes to dealing with significant digits, for addition/subtraction, we go with the lowest significant amount for decimals, in this case,
560.589 <--- has 6 significant digits, accurate to the 1000th place
23.47 <--- has 4 significant digits, and is accurate to the 100th place
thus, our answer will have to be rounded up in 2 significant decimals, or 537.12
and that only has 5 significant digits, since is rounded up to the 100th place.