It means that the correct value could be anything between 243500 and 244500 square kilometers.
it mean signs
The significant figures in 314.721 meters are 6. All non-zero digits are significant, as well as any zeros between non-zero digits.
Probably "number of significant figures = 2".
The greater the number of significant figures, the greater the precision. Each significant figure increases the precision by a factor of ten. For example pi = 3.14 is accurate to 3 significant figures, while pi = 3.14159 with 6 significant figures is a more accurate representation.
There would be five. The only time you do not count figures as significant is if they are zeroes behind a decimal, but before any other figure. Ex/ 0.000501 only has three significant figures, while 1.000501 has seven.
Exactly what you typed. 144.78 rounded to 2 decimal places is 144.78. You may mean significant figures, in which case it would be 1.4*10^3 (2 significant figures).
It has 4 significant figures.0.007080 has four significant digits.
It isn't clear what the question is. If you are supposed to multiply or divide, and if by "signification figures" you mean significant digits, do the multiplication (or division), then round to three significant digits - since the least-precise of the numbers only has three significant digits.
If you are looking at this from a maths perspective, the 'significant figures' are the number of digits counting from the first non-zero digit, so the number of significant figures in 10.0 is three. You may be asked a question, and told to give the answer 'to three significant figures'. This would mean the answer would look something like '12.2' or '0.0254'. This is in contrast to decimal places, which refer to the number of digits after the decimal point. For example, the number 10.0 is quoted to one decimal place.
if you mean PI squared + PI squared / by 2 then that is.... 4.9298 solved on paper ... BUT if you mean what you said, the answer is YUMMY!
n^3 mean a number Squared by 3
The rules of "significant figures" tell you how many of the digits in your answer can be trusted and how many are trash. Without knowing those rules, you may get an answer with 15 digits in it, and think that you have the greatest answer there could be, and not realize that the last 12 digits are wrong and don't mean anything.