1. Five times three equals 15.

2. Five multipled by three equals 15.

I always thought "times" is a verb( with a somehow special usage) before I encountered "twice three" today.

So sentence (1) means five "three"s are 15, whereas sentence (2) means three "five"s are 15. They are basically different. Do I get it right?

I'm not sure, but as I understand it, the multiplicand is "3" and multiplier is "5" in sentence(1). It's the other way around in sentence(2), the result is the same though.

Hello, Robby and Gustavo—Interesting topic. I once shared your sense, Robby, that "times" is a verb in sentences like (1), just as "plus" felt like a verb to me in sentences like "One plus one is two." But "plus" and "times" in this type of usage are actually categorized as **prepositions**. Quirk *et al.* call them "marginal":

**Quote**: "*Less, minus, plus, times,* and *over* form a special group in their use with numerals . . .:

*6 + 2* is read as 'six plus two'.

- Quirk, Greenbaum, Leech, and Svartvik. A Comprehensive Grammar of the English Language, p. 667. Longman, 1985.

In another usage, however, *times* (along with *twice, thrice, double*, etc.) is categorized as a **predeterminer** (see Quirk *et al.*, page 257). They give the examples *double the sum* and *twice my salary*. The latter expression could, of course, be reworded *two times my salary*.

Robby, it seems to me that your inclination to see the multiplier and multiplicand as being reversed in examples (1) and (2) may be due to your trying to parse *times* as a predeterminer in (1), such that the sentence might be read with *fifteen* as the subject:

**(3) Fifteen equals five times three. (15 = 5 x 3)**

I believe that (3) can be read in two different ways. The way it would normally be read is as a mathematical formula, the words standing for "15 = 5 x 3," and on that reading "times three" is a prepositional phrase. However, it seems possible to interpret it in such a way that it is analogous to (4) below:

**(4) Fifteen [cars] equals five times three [cars].**

Translation: "Fifteen cars equals five times *that number of cars,*" where "that number of cars" is three cars (15 = 3 x 5).