億 hundred million, 10**8 15 strokes taught in grade 4 old JLPT 2 #716 in newspapers Readings Onオク In Chinese 亿, traditional 億 Words written with it 一億 いちおく 100,000,000 億 おく hundred million N4 十億 じゅうおく 1,000,000,000 １００億 ひゃくおく 10,000,000,000 数億年 すうおくねん several hundred million years 億万 おくまん millions and millions