Devils graduate in odd-numbered years, goats in even-numbered years.  From Mary Washington's 1985 yearbook.  See How to Hoodoo Hack a Yearbook.

Long division with Roman numerals -- so rarely taught anymore.  From Purple Parrot, 1940.

This is from a contest requiring one to total all the numbers pictured.  From The Goblin, 1928.

People's 13 top fears about numerology:

If you have trouble with math, maybe it's not you -- "Numbers don't add up."  From Antioch News, Oct. 1996.

From The Film Daily, 1945.

People turn into numbers in the endpapers of Northeastern's 1984 yearbook.

You've heard of the art crowd, but did you know they're color-by-number?  From The Art Crowd by Sophy Burnham, 1973.

"When the sky comes down and the stars look like numbers."  An illustration by Maud and Miska Petersham for Carl Sandburg's Rootabaga Stories.  From Current Opinion, 1922.

This illustration from an 80s computer gaming book offers a perplexing puzzle.  How do the answers to each computer screen make sense?

From Inside Basic Games by Richard  Mateosian, 1981.

Answer: "Note that three of the computer screens each feature one number unlike the others. The proper answer is always the digit whose position in the computer keyboard number pad corresponds to the odd position on the screen. For example, in the first screen, the odd number is at the bottom left, the position of the "1" key of a keyboard's number pad. The second screen's odd number is at the center, where the "5" is located on a key pad. There are no odd numbers in the third screen, hence an answer of "0.". (The answer is in black text on the black background. Highlight it to view.)

You've heard of "growing numbers."  Here's how they're cultivated.  From Der Guckkasten, 1918.

You didn't need a math professor to tell you that, no matter what the song says, one is not "the loneliest number."  (But if you actually do need a math professor to tell you, Dr. Mason Porter of UCLA is there for you.)  The lyric needs text doctoring, since one divided by two is in fact a half (.5):

Original: One is a number divided by two.

Revision: One's the remainder when you once halve two.

If we do say so ourselves, our revision offers not only homophony (one's/once) but also wordplay (halve/have).  (Don't knock us, for if we received even half the literary criticism we deserve, we wouldn't have to analyze our own work.  Hint: this is your invitation to be part of the solution.)

Our headline from Greensboro's 1975 yearbook.

Here's an occultist's figure of the number nine, from Letters from an Occult Student by Jane Oliphant Muscat, 1922.

From Popular Mechanics, 1930.

From Grip, 1891.