日

Don't confuse with

日 (rì, sun) is the simplest: a short box with one line across the middle. 目 (mù, eye) is a taller box with two lines inside, like eyelashes. 白 (bái, white) looks like 日 with a small stroke added at the top-left corner, like a ray of light. 百 (bǎi, hundred) is 白 with one more horizontal line stacked on top — literally "one" (一) plus "white" (白).