Kanji number riddle...things

A couple months ago, my friend's girlfriend taught me a couple of interesting kanji-riddle-number things, for lack of a better term. I beg your indulgence if you're not very familiar with kanji, but you may find this interesting nonetheless.

米 （こめ；べい）, usually pronounced "kome" or "bei," is the kanji for "rice." It can also mean "America." I imagine this is because America is the country with vast fields of grain. But this kanji can also mean 88 years old. Let me show you why.

八 is the kanji for "eight."

十 is the kanji for "ten."

We draw 米 by this process:

1) We draw two intersecting lines, like the kanji for 10.

2) We add two diagonal lines orginating from the intersection, like the kanji for 8.

3) We add two more diagonal lines, this time sticking up, like an upside down "8" kanji.

4) Ta-daa...here are the components: 10, 8, and 8.

I suppose since 10 x 8 + 8 = 88, 米 can represent 88 years old.

Kudos and an e-cookie for anyone who can tell me what number 白 represents and why.

Know any other kanji-riddle things like this, or if these have a proper name? If so, please share them!