数算练习告诉我们算术运算的原理，而不是单单的记忆和不断演算。

"I decided as long as I'm going to hell, I might as well do it thoroughly."

数学不是关于数字、方程、计算或算法的：它是关于理解的。

We don't read and write poetry because it's cute. We read and write poetry because we are members of the human race. And the human race is filled with passion. Medicine, law, business, engineering: these are noble pursuits and necessary to sustain life. But poetry, beauty, romance, love...these are what we stay alive for.

In theory, there is no difference between theory and practice. But, in practice, there is.

If you plan on being anything less than you are capable of being, you will probably be unhappy all the days of your life.

我们关注的不是数字，而是产生数字的那些东西。

Quiet people have the loudest minds.