If there is a problem you can't solve, then there is an easier problem you can't solve: find it.

The result of the mathematician's creative work is demonstrative reasoning, a proof; but the proof is discovered by plausible reasoning, by guessing.

If there is a problem you can't solve, then there is an easier problem you can't solve: find it.

It may be more important in the mathematics class how you teach than what you teach.

The future mathematician ... should solve problems, choose the problems which are in his line, meditate upon their solution, and invent new problems. By this means, and by all other means, he should endeavor to make his first important discovery: he should discover his likes and dislikes, his taste, his own line.

It is better to solve one problem five different ways, than to solve five problems one way.

The teacher can seldom afford to miss the questions: What is the unknown? What are the data? What is the condition? The student should consider the principal parts of the problem attentively, repeatedly, and from from various sides.