# What do we call the combination of a number and a unit

As a Software Engineer I give my best to find descriptive names for specific concepts. That is a very important task to reduce software complexity. Naming concepts can be really hard and today I’d like some help.

• This is a number: 1
• And this is a unit: kg

What do you call the combination of both? (e.g. "1kg")

1. Unified number
2. Typed number
3. Number specification
4. Number unit
5. Measurable number
6. Comparable number
7. Discriminated number
8. Tagged number

But I believe they are confusing and do not describe the concept well enough. My favourite is “discriminated number”.

Is there a name for that concept in the English language? It doesn’t have to be a single word. But more than two words is impractical and people will find other short words that do not express the concept clearly enough.

The word I am looking for will be used like this: “This is an invalid ___. That’s why you cannot run your program correctly.”

or

“I’ve configured all valid ___s but the program still doesn’t recognize this variation!”

• Maybe you can call that a quantity – Jim Dec 7 '18 at 23:51
• You might use "value" unless that term is used for something else. – J. Taylor Dec 8 '18 at 0:21
• Possible duplicate of Numbers and units – Laurel Mar 5 '19 at 21:49

This is the definition of a (physical) quantity. E.g. from Wikipedia:

A physical quantity can be expressed as the combination of a magnitude expressed by a number – usually a real number – and a unit: nu where n is the magnitude and u is the unit.

My first thought when I saw the question was "measure", although I vaguely recall from my days as a math über-geek that they use that term for something different from what you're talking about.

My second thought was "measurement", but that's not right.  While a number+unit could be the result of a measurement, it could equally well be a guess or a specification.

Plain numbers like 1, 17, 42, e and π (pi) are called "unitless numbers" (and I note to my surprise that my spell-checker gags on "unitless", although it does tolerate "unit-less").  So you might call your thingies "unitful numbers"  or "unitted numbers"  (and I'm not surprised to see that the spell-checker rejects those as well).  These may be the best answers, but you would have to explain them to people.

P.S. Next time you go to the thesaurus, you might want to look at "scalar" and "vector".  A scalar is a number — possibly unitless, but possibly having a unit of distance, speed, acceleration, force, etc.  A vector is a scalar combined with a direction (for example, speed is a scalar but velocity is a vector), so the dichotomy is similar to yours.

I don't know if there is a definitive answer, but I have used some terms in technical documentation to describe this type of data.

• unit measure or unit measurement
• labeled value
• quantified number
• parameter (a term for a variable in a process that by definition requires a quantity and a unit)

I'm not sure that the definition of "(physical) quantity" covers all cases. What about "1 hour" for example? That would not fit the definition of physical and is a quantity somewhat loosely.

• An hour is just a day divided into smaller pieces, and a day is a physical quantity. We need to keep pushing back against the silly reification of space and time that causes so much confusion. There aren't any samples of space or time kept in a box in a lab. But there are reference meter sticks and reference clocks. Our language is terribly unhelpful in distinguishing between the two because people are terribly confused about the difference. But an hour has no more of a special relation to time than a fruitfly. It's just handier. – Phil Sweet Jul 12 '19 at 16:20
• btw, I'm not the downvoter. – Phil Sweet Jul 12 '19 at 16:22
• A "day" is a physical quantity? You have a very broad definition of "physical". I believe the standard definition says "having form and mass" is "physical." You know, like words are not physical, but a book is. – user8356 Jul 12 '19 at 17:25
• Hope whoever downvoted perfectly valid answers feels good about being a critic without giving any input. – user8356 Jul 16 '19 at 14:57