Sig Fig Clarification: 150. vs 150 - Is it Correct?

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Homework Help Overview

The discussion revolves around significant figures, particularly focusing on the interpretation of numbers like 150 and 150. Participants are exploring how the presence of a decimal affects the significance of trailing zeros and the implications for reporting measurements.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the rules surrounding significant figures, particularly in the context of numbers with and without decimals. There is an exploration of why a decimal point in a number like 150. indicates that the zero is significant, while 150 does not imply the same.

Discussion Status

The discussion is active, with participants sharing their understanding and interpretations of significant figures. Some guidance has been offered regarding the representation of numbers in scientific notation to clarify the number of significant figures intended.

Contextual Notes

There appears to be some confusion regarding the definitions and implications of significant figures, particularly in relation to measurement precision and the interpretation of numbers with trailing zeros.

dnt
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just to clarify on sig figs...for example if a question asked what is the volume of a box that is 85 m by 92 m by 95 m, the answer is 742900 m^3 but since each number has 2 sig figs, the answer must be reported as 740,000 m^3?

is that correct?

also, 150 has 2 sig figs but 150. has 3...right?

thanks.
 
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dnt said:
just to clarify on sig figs...for example if a question asked what is the volume of a box that is 85 m by 92 m by 95 m, the answer is 742900 m^3 but since each number has 2 sig figs, the answer must be reported as 740,000 m^3?

is that correct?

also, 150 has 2 sig figs but 150. has 3...right?

thanks.

You've got it.
Actually, it's probably better form to write it as:
[tex]7.4 \times 10^{5}[/tex]
Since that will leave no doubt about whether the zeros are significant.
 
thanks.

regarding the "150 vs 150." - i know how many sig figs it has but can someone explain WHY the decimal at the end makes the 0 significant in 150. compared to only 150?
 
150. is read as 150.0
 
whozum said:
150. is read as 150.0
umm..i don't think so, i think 150.0 has four sig figs, 150. has three, and 150 two.



dnt, the decimal in 150. is just a way of saying that, to the limits of your measuring tool, for example: this stick is exactly 150. metres , not 149, not 151, but 150.
and in the case of 150.0, it would be implied that your measuring tool can measure to the tenth of a metre and for example you could say: this stick measures exactly 150.0 meters, not 150.1 not 150.2, but 150.0, though you know nothing about the second decimal place. it could be 150.01, 150.0[1-9], u don't know, its too precise for ur measuring tool. u get it?
 
It would, of course, be better to write them as 1.5 x 102 if you intend 2 sig figures, 1.50x102 if you intend 3, 1.500x102 if you intend 4.
 
DB said:
umm..i don't think so, i think 150.0 has four sig figs, 150. has three, and 150 two.

i didnt say it IS 150.0, it is understood as 150 and nothing else. exactly 150, it has 3 significant figures.
 
sorry, i missunderstood ur statement
 

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