Emil Morrison, age 16, of Pittsfield, Mass., for his question:

HOW DID WE GET THE ABBREVIATION FOR `NUMBER'?

When you abbreviate the word "number" you write "No." You don't write "Nu." as may seem logical because of the word's spelling.

The abbreviation No. for number is from the Latin word "numero," meaning "by number." It is usually written with a capital letter "N" and is used chiefly in business and in technical English.

In many foreign cities the abbreviation No. appears in front of a house number in a street address. This practice is not used in the United States or Canada, however.

Numbers are ideas. We think of a number when we consider how many objects are in a certain group. Numerals are names for number ideas.