Tā bùsuàn cōngmíng, dàn qínnéng-bǔzhuō, zuìzhōng kǎoshàng le míngxiào.
He's not exactly bright, but diligence makes up for lack of talent, and he finally got into a top school.
Tips
history
Traced to the Song poet 邵雍's 《弄笔吟》: 将勤补拙 - 'use diligence to patch what's clumsy.' The four-character form became the standard idiom.
usage
A very common encouragement phrase from teachers and parents. Often paired with 笨鸟先飞 ('the slow bird flies first') for the same hard-work-beats-talent message.