1,131. Teaching on Shabbos

165:14 On Shabbos, children should not be taught a new subject that they haven't studied before. This is because we are not allowed to exert ourselves on Shabbos. That which they have already gone over once may be reviewed on Shabbos.

165:15 If a child found something, and certainly if something was given to him as a gift, it is prohibited to steal it from him.