How to easily remember the number Pi (π)?

How I wish I could calculate pi easily today. Archimedes, artist, engineer, your Syracuse honor is forever remembered by these wise verses.

π = 3.141 592 653 589 793 238 462 643 383 279


How to easily remember the order of the planets?

My Very Educated Mother Just Served Us Nachos.


Order of the planets from the Sun:
Mercury - Venus - Earth - Mars - Jupiter - Saturn - Uranus - Neptune.



How to easily remember the color code for determining the resistance of a resistor?

Big Brown Rabbits Often Yield Great Big Vocal Groans When Gingerly Slapped.


Digit Color
0 Black
1 Brown
2 Red
3 Orange
4 Yellow
5 Green
6 Blue
7 Violet
8 Gray
9 White

Note that two colors start with the letter V: "Green" and "Violet." Green comes before Violet.
Two colors start with the letter B: Blue and White. Blue comes before White.
The sequence starts with 0 for Black and ends with 9 for White.

We can relate this to the order of the seven colors of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. The color indigo is often subtle, and typically we observe six dominant colors.

Visible Spectrum