# What is the correct way to write this uncertainty?

$$Z = 23,8937 * 10^{-5} [u]$$ $$u(Z) = 3,721 * 10^{-7} [u]$$

I have to write this uncertainty in complete form. Would this be correct? $$0.0002389 \pm 0.0003721$$

• What's incomplete about the first version? – ACuriousMind Jun 3 at 16:43
• My guess it does not answer some standards, since my teacher made this task. It needs to be done as one statement – Murad Davudov Jun 3 at 16:46
• Are you using a comma as a decimal point in the first two lines but a period as a decimal point in the third? If so, that’s confusing. – G. Smith Jun 3 at 19:43

The straight forward way it to round the error to the most significant digit, and keep the measured value to the accuracy of the error, thus the value is $$0.0002 \pm 0.0004$$.