My Calculator app is stuck remembering the same value after update to High Sierra

I can only advise you not to rely on this Calculator "widget" from the Notification center.

Much better alternatives (IMHO):

a) use the "real" Calculator application (the one in your Applications folder)

b) use Spotlight (extremely handy, you can even type the expressions, save them on a text file, copy and paste, etc)

c) use a Service like "CalcService". It can be applied to any arithmetic expression written as text in any application

d) use another calculator, like the already mentioned PCalc

I often use a), b) or c), depending on the circumstances, but most often I just go with Spotlight: type command-space then type whatever expression I need, like: 5% * 1829 (here the comma is the decimal separator, set in the international preferences)

Is the Calculator app unresponsive, or does it just launch with that same value all the time?

For the latter please read Resolve issues caused by changing the permissions of items in your home folder - Apple Support.

new example #3 with incorrect calculations:

10+50-10*2=40

I may not be able to help you the other issues, by this one is NOT incorrect.

That is how mathematical operations work. Basic rules of arithmetic.

Multiplications and divisions have higher priority than additions and subtractions.

If you want to do multiplication last, use parentheses.

(10+50-10)*2=100

10+50-10*2 = 10+50-(10*2) = 40

I have the exact same problem and it's so annoying! My calculator is stuck on the answer to the very first equation I entered after upgrading to 10.13. I can clear it as much as I want, but when I close the notification center and open it again, it's right back to the same number.

Same here in different machines running High Sierra. Calculator is now impossible to use as values reset themselves if you click anywhere outside (e.g. looking for an entry value on the browser). Amazingly annoying.

I have this exact same problem and it makes the Calculator app unusable on High Sierra. I updated both my iMac and MacBook, and both were stuck on the original value before the upgrade took place.

I followed the advice to clear the "com.apple.ncplugin.calculator.plist" file from /Library/Containers, which blanks the readout on the calculator to 0, but the problem persists. It now just reverts to 0 on the read out.

It's infuriating. You can be mid-way through a long calculation, only to have it blank when you next refer to it.

Such a basic feature. It's really incredible it hasn't been picked up before release, or even now, that a software update hasn't been made to solve this bug after many many months and numerous OS bug fixes. Getting tired of waiting for it to be acknowledged by the wider community and more so by Apple themselves.

I can't reproduce this - assuming that you are not *quitting* the Calculator application between uses. If I quit and restart, it reverts to zero, but I can keep it open while changing to other applications, and it never reverts to zero on its own.

No, I use the Calculator App that's pinned into the Notifications Centre, sliding it from the right to reveal.

Entering a calculation, sliding to hide the notification centre, then sliding again to reveal and add to the ongoing calculation. I can literally see the calculation blank before the notification centre fully slides open again.

It wasn't an issue in previous MacOS'

I think its a notification centre bug, causing the calculator to re-set on opening, or revert to it's last known value when High Sierra was originally installed.

I haven't tried to use the standalone Calculator app, but I will, because the Notification Centre Calculator app is useless with this bug present.

FWIW, one of the users here said they spoke with Apple and was told the "zeroing out" was by design.

You may want to take a look at PCalc in the App Store. It retains the last value and also can be integrated into the Notification Center. It's what I use.

Seem's fairly mad to have a calculator "zero out" mid way through a calculation. Maybe Apple OS designers don't make any numerical calculations at all.

I can even enter the next function (+, x,/, -) to pre-empt the figure that will be entered next, and when I come to enter the next figure, I see the Notification Centre Calculator blank and revert to zero.

No-one in their right mind would practically design a calculator that fights against it's users inputs.

I'll take your advice and look at 3rd party options. Many thanks.

One thing I forgot to mention. Whatever solution you decide on, different methods seem to evaluate expressions differently. You may have "fiddle" with the expression to get the correct result. Personally I haven't run into the problem with PCalc but that doesn't mean it can't happen.

See the answer by mons.fractus in this thread:

Re: Calculator widget on notification panel

Can you be more specific? Doesn’t the C button work? What happens when you enter any values or operations to perform?