If converting 5.15 days to seconds = 444960 seconds, what is 444960 in sigfig terms?

5 significant figures or #4.4496xx10^5# seconds

To get from days to seconds, you used a series of conversion factors.

More specifically, you wrote

#5.15color(red)(cancel(color(black)("days"))) * (24color(red)cancel(color(black)("hr")))/(1color(red)(cancel(color(black)("day")))) * (60color(red)(cancel(color(black)("min"))))/(1color(red)(cancel(color(black)("hr")))) * "60 sec"/(1color(red)(cancel(color(black)("min")))) = "444960 sec"#

Now, the final result must have the same number of significant figures that you started with.

All those conversion factors are exact numbers, which means that you can consider them to have an infinite number of significant figures.

Simply put, you started with three sig figs in #"5.15 days"#, you must end up with three sig figs in #"444,960 sec"#.

The way it is written now, the answer has five sig figs, which means that you will need to round it to three sig figs.

The answer will thus be

#"5.15 days" = color(green)("445,000 sec")#

You can also express the answer in scientific notation if you want

#"5.15 days" = 4.45 * 10^5"sec"#