米 pictures grains of rice scattered on a threshing cross — six dots-and-strokes that have meant 'hulled rice' since the oracle bones. Look at it and you can almost see the grains fly.
米 is the staple of southern China: 米饭 (cooked rice — with 饭 you learned), 大米 (raw rice). It moonlights as the metric meter (一米 = one meter) purely for its sound. The saying 巧妇难为无米之炊 — 'even the cleverest wife can't cook without rice' — is China's 'you can't make bricks without straw'. Rice isn't a side dish; it IS the meal, and everything else is 菜 to go with it.
Grains flying off the threshing cross — RICE.
米 also means 'meter' — so 100米 is the 100-meter dash, run on rice-power.