“In fact the smallest units of matter are
not physical objects in the ordinary sense; they

are forms, ideas which
can be expressed unambiguously only in mathematical language.”

There are an estimated 1.618 million web sites dedicated to recreational
mathematics. Many of them feature interesting and useful material;
but there is mammoth duplication of content. I strongly desire
**not** to contribute to the clutter, hoping to offer perspectives
sufficiently unique that they will not be encountered elsewhere.

Doubtless these materials will interest only a small percentage of
visitors. No advanced learning is required here, though;
a reasonable awareness of ~~high-school~~ math is sufficient.

*A Challenge to Mathematicians:* Solve the "Black Box" Puzzle

A Special Continued Fraction for Square Roots

Pencil & Paper Square Roots Using Continued Fractions

Some Tips & Tricks for Mental Calculations

Be Your Own Perpetual Calendar — Calculate Dates in Your Head

The articles in this section are designed to be assimilated in numeric sequence. Each page features ideas or methods previously introduced.

1: Introduction to Programming a Four-Function Calculator

7: Extra Decimals for Square Roots