Significant figures...again?

Question

I have another question about significant figures, but this time its about rounding. Can someone explain the concept? and examples will be really helpful. Thx!

Answer 1

when you round to significant digits you simply go one more than the signfificant digit and round

for example 182300   has 4 significant digits

round to 3 significant digits

round the 3 down

182000, now you have 3 significant digits

.000568   had 3 significant digits  

round to 2 significant digits

.00057

560.42 has 5 significant digits round to 3

560  don't use a decimal point, or it will add a significant digit

hope that helped