A.

1. The five Great Lakes: Huron, Ontario, Michigan, Erie, Superior.

2. The colors of the rainbow, in order: Red, Orange, Yellow, Green, Blue, Indigo, Violet.

3. This fictitious disk jockey’s business card gives you the months of the year, in sequential order: June, July, August, September, October, November, December, January, February, March, April, May.

4. For beginning French students, “one egg” is un oeuf. There are many mnemonics for words in almost every language. Other French ones: “Part II [partout] is everywhere,” and “Pluto [plutôt] is coming soon.” For Hebrew pronouns: “Me is who, who is he, and he is she” (that is, mi means “who,” hu means “he,” and hi means “she”). But in Japanese, mi = 3, hu = 2, hi = 1 and (in a different numeral sequence) shi = 4.

5. In music, the five lines on the treble clef are e, g, b, d, f, as in Every good boy does fine. The spaces are f, a, c, e, or face. For the lines on the bass clef, use “Good boys do fine always” (g, b, d, f, a), where the spaces are remembered by All cows eat grass (a, c, e, g).

6. The spectral types of “main sequence” stars, starting with the hottest and brightest: O, B, A, F, G, K, M. (Our own yellow sun is merely around G7.)

7. The hierarchy of biological classification levels: Kingdom, Phylum, Class, Order, Family, Genus, Species. (Kingdoms are now grouped in larger units, the Eukaryotes, Prokaryotes, and Archaebacteria, which I have proposed should be called “Empires”; at the other end, Species are subdivided into “Varieties.” A nine-word mnemonic can be coined to include these extensions: “Every keen person can obtain fresh green salad veggies.”

8. The color code on the stripes circling electrical resisters, for the digits 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, are (in order): black, brown, red, orange, yellow, green, blue, violet, gray, white. (Note the omission of “indigo” from A.2. above.)

9. The 12 pairs of cranial nerves, which every student of human anatomy must memorize, in order are: olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, acoustic, glossopharangeal, vagus, (spinal) accessory, hypoglossal. A companion mnemonic, to remember which nerves are sensory nerves, or motor nerves, or both, in the same order is: Some say “marry money,” but my brother says, “Bad business marry money.”

10. The successive digits of “pi,” the ratio of the circumference to the diameter of a circle, are given by the number of letters in the words of this mnemonic: “3.14159265358979.” There are many other mnemonics for pi, both shorter and longer, and in many different languages. A short one, for 3.1416, is “Now I have a number.”

B.

1. “Spring forward, fall back.”

2. “Lefty loosy, righty tighty,” or simply “Clockwise to close.” This works for screws, garden hose taps, and most other valves, but natural gas valves operate in the reverse direction!

3. “Thirty days hath September, April, June, and November. All the rest have thirty-one. Save February, all alone,

Whose days are only eight and score, But leap year brings it one day more.”

4. “I before E except after C,

Unless pronounced A, as in neighbor and weigh.”

While this rule works for believe and receive, it has dozens of exceptions. (What general principle can explain siege vs. seize?) Today, instead of a mnemonic, one can use spell-check!

For bawdier mnemonics, e.g., for A.8 or A.9, ask someone who studied electrical engineering or pre-med anatomy, respectively.