I’m honestly surprised you’ve never had to do that, because it happens to me all the time.

Like when I’m approaching a junction on the road and the satnav suddenly changes from saying 0.5 miles to like 500 yards, that’s jarring and breaks my mental countdown. (In Britain, the roads are imperial, yes it’s a pain.)

Or if I’m cooking an old recipe and it needs 12oz of something, but I’m doubling the quantity, suddenly I need to know what that is in lb and oz because my scale doesn’t just tell me 24oz.

Or if someone says they’re 5’ 8" tall, I have to know how many " in a ’ to conceptualise how close that is to 6’.

Meanwhile, I know when I’m out hiking what my pacing is for 100m, and if I’ve got 2.5km to go, that’s 25 lots of pacing.

Or when I’m sewing, and fabric is sold by the metre but all the pattern pieces are measured in cm or mm.

And not strictly related, but it’s handy being able to measure out water in an unmarked container using a weighing scale and the fact that 1l=1kg.

Everyone’s got something to hide.

For example, I like to keep my credit card number secret from criminals.

I’m happy with my Brother laser. Can’t comment on their recent models as it’s 10-15 years old! It was about £200 up front and a replacement toner is about £60, but it lasts and lasts rather than inkjet which seemed to need new cartridges every month. No issues with needing internet, and it accepts third party toner fine (though I’ve had quality issues with some brands).

We (uk scout group) use g suite or whatever they call it these days. The Google connection isn’t ideal, but we get it completely free, the t&cs and level of control over it are a lot better than consumer gmail/drive, the learning curve for techphobic users is about as shallow as possible, and we don’t have to spend volunteer time on maintaining the platform. So definitely worth it for us but your situation may vary.