A worksheet is only as useful as its appropriateness to the needs of the children and the learning objectives. It is not intended to be a means of keeping children quiet while teachers attend to more pressing matters. On the other hand, a sufficient number of well-designed sheets can be of considerable benefit to a busy teacher, especially when dealing with a large number of children. The golden rule is to ensure that they are not overloaded with words and facts. If sheets are published ones, you may need to modify them for your group of children, as they are not necessarily appropriate as they stand.