/sci/ - Science & Math

>>9449839
there are 3 rules. they are really straightforward. how is that hard?

Zeroes in front of non-zero digits don't matter because they can always be removed by scientific notation. 9E-4 instead of 0.0009
All other digits matter.

One additional rule your list doesn't cover. The number of trailing zeros means something too.
If I multiply 14.2 by 6.7 I get 95.14
This should NOT be written as 95.140000 because that implies that I know the answer to that accuracy.
"Real" data (some measurement you take) always contains some uncertainty. If I can read a thermometer to a tenth of a degree, I say your body temperature is 98.3 Not 98 and not 98.3000
The answer to a calculation should not have more significant digits than the least-accurate number which went into the calculation. A digital thermometer might read 98.300000 but if it's really only accurate to the nearest degree, everything after the decimal point is meaningless garbage.

>>9449839
Convert everything to engineering notation and it makes more sense.

40.7 => 4.07e1
87009 => 8.7009e4
0.009587 => 9.587e-3
0.0009 => 9e-4

It all boils down to one rule : restrict precision in order not to lose exactitude.

>engayneers/physishits
>on my board

>>9449839
>4001.5 +- 100
>hurr 5 significant figures

>>9449839
Pro-Rule Keep as many digits as you can but remember how many are significant till you get to the end

>>9450661
go back to studying homophobic algebra you fuckin weeb

>>9449941
>If I multiply 14.2 by 6.7 I get 95.14

shouldn't you round 95.14 to 95, since 6,7 is the lowest figure number

>>9449941
4÷2=2 with only 1 significant digit

>>9449964
>engineering notation
>4.07e1
L0Lno fgt pls

I literally don't bother with them and just restrict everything to 3 sig figs. If the dumbass measuring my data can't give it in 3 sig figs then I will assume it is accurate to that point

>>9450754
>algaybra
>not superior differential geometry
plens, all plens

>>9449839
>Zeros in front of nonzero digits are not significant
wut. "in front" is a terrible descriptor for this shit.

Just convert the calculated results to scientific notation. Then express the result with the same number of figures as the "less accurate" observed value used in the calculation (i.e. the one with the lowest number of significant figures).

Thanks for the help

>>9452394
>calls physishits out on their shit
>a fucking geometer
>a differential one at that
your work is just as applied as any mechanical engineer's, you worthless cog.