Mathematics is not a spectator sport!

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

The first and foremost duty of the high school in teaching mathematics is to emphasize methodical work in problem solving...The teacher who wishes to serve equally all his students, future users and nonusers of mathematics, should teach problem solving so that it is about one-third mathematics and two-thirds common sense.

When introduced at the wrong time or place, good logic may be the worst enemy of good teaching.

Analogy pervades all our thinking, our everyday speech and our trivial conclusions as well as artistic ways of expression and the highest scientific achievements.

There exist a lot of questions that the fools can ask, and the intelligent cannot answer.

Solving problems is a practical art, like swimming, or skiing, or playing the piano: you can learn it only by imitation and practice.