Question #15f43

1 Answer
Mar 17, 2017

Answer:

#5#

Explanation:

The first thing to look for when trying to figure out how many significant figures you have in a measurement are non-zero digits.

Non-zero digits are always significant, regardless if they are added before or after the decimal place. In your case, you have three non-zero digits

#color(black)(color(red)(7)0. color(red)(8)0color(red)(4) -># three non-zero digits

so you know for a fact that the measurement has at least three sig figs.

The first zero

#7color(blue)(0).804#

is significant because it follows a non-zero digit, i.e. #7#, and it is being followed by a non-zero digit, i.e. #8#. Zeros that are "sandwiched" between two non-zero digits are always significant.

Notice that the second zero

#70.8color(blue)(0)4#

is also sandwiched between two non-zero digits. This zero follows #8# and it is being followed by #4#, so you know for a fact that this zero is significant.

Therefore, you can say that the measurement given to has #5# significant figures

#color(black)(color(red)(7)color(blue)(0). color(red)(8)color(blue)(0)color(red)(4) -> {("three non-zero digits"), ("two sandwiched zeros") :}#