For the best results with your children, spend only half the money you think you should, but double the time with them.
Mathematics is not a spectator sport. You have to do it to understand it.
最有趣的空间是那些介于两者之间的空间——意义在其中产生的缝隙。
时间的流逝既是祝福也是诅咒。
激励措施的微小变化可以导致行为的巨大变化。