How many significant numbers are in 9400?

Answer 1

There are 4 significant numbers in 9400 . If in a number decimal is absent , then all digits in that number are significant . Ans #2 Since the example you give is not a measurement, it must be a count or an absolutely precise number. As such, all digits are significant...and all digits out to infinity are significant. 9400 dogs is an absolute count because you can't have a fraction of a dog. It is, however, irrelevant to discuss precision of an absolute count because it is infinitely precise. 2 measurements of 1.5 inches means multiply 2 (absolutely precise) × 1.5 inches (precise to the tenth of an inch) = 3.0 inch (precise to the tenth of an inch). Two baskets with four kittens each is exactly eight kittens. Since it is an absolute count, it is absolutely precise. If you need to represent the precision of an estimated count, you can say 9400 ±100 dogs This means that you have 2 significant digits: 9400 give or take a hundred. Any math you do with that estimated count will need to carry that imprecision along with it. The estimated part of a measurement is likewise significant. If the number is a measurement, ex. 9400 inches, the zeros are not significant because they are only placeholders. For them to be considered significant they would need to be barred (write a small bar above them such as you do for a repeating decimal). For measurements, the rules go: * All non-zero digits are significant; * Zeros between significant digits are significant; * Zeros that serve only as placeholders are not significant unless marked. If the measurement had been 9400.0 inches, the zero trailing the decimal point is significant because it is not serving as a placeholder. It is a meaningful part of the precision of the measurement. It says that you estimated the measurement to the tenth of an inch. If the measurement were 0.0094 inches, the zero to the left of the decimal point is not significant. It is placed there so you don't confuse the decimal point as a period belonging to the sentence that came before. The next 2 zeros are only serving as placeholders and they, even if marked, do not improve the precision. It would be meaningless to mark them as significant. This measurement has only 2 significant digits.