虽然工资不高，但他性格乐观，懂得知足常乐。

Suīrán gōngzī bù gāo, dàn tā xìnggé lèguān, dǒngde zhīzú chánglè.

Although his salary is not high, he is optimistic and knows how to be content and happy.

奶奶总说，人要知足常乐，不要总是跟别人比较。

Nǎinai zǒng shuō, rén yào zhīzú chánglè, bú yào zǒngshì gēn biérén bǐjiào.

Grandma always says that people should be content and thus happy, and not always compare themselves with others.

学会知足常乐，可以减少很多压力和烦恼。

Xuéhuì zhīzúchánglè, kěyǐ jiǎnshǎo hěnduō yālì hé fánnǎo.

Learning to be content can reduce a lot of stress and worries.