In chemistry, one often has to use decimal exponents: 10^{-4.6} for the value of a reaction constant. I'm usually using siunitx to type numbers in scientific notation with \num{4e5} for instance. However recent versions don't allow decimal exponents anymore. I'm now left with many files filled with commands like \num{1e-5.6} that don't compile anymore.

What other package would parse numbers with decimal exponents ?

  • you can always use the option for siunitx v2 compatibility Feb 23, 2022 at 8:00
  • This has come up with a couple of people and I'm thinking about it: my issue is that the point of an exponent for a quantity is in-part that it links to SI prefixes. That only works for integer exponents. Can you give a fuller example which shows the use case with units, etc.?
    – Joseph Wright
    Feb 23, 2022 at 8:03
  • Personnally, I don't need decimal exponents for the \SI command, only for the \num command where there is no problems with units.
    – wilk
    Feb 25, 2022 at 14:50

1 Answer 1


You could write a macro yourself, assuming that you don't have any complicated use cases. Of course, you won't have access to any of the other nice features of siunitx.


      #1 \cdot





MWE output

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