2. Through Constructive Instinct.--The child's delight in motor expression is closely associated with his instinctive tendency to construct. When, therefore, new knowledge can be presented to the child in and through constructive exercises, he is more likely to feel its value. Thus it is possible, by means of such occupations as paper folding or stick-laying, to provide interesting problems for teaching number and geometric forms. In folding the check-board, for example, the child will master necessary problems relating to the numbers, 2, 4, 8, and 16. In learning colour, it is more interesting for the child to study different colours through painting leaves, flowers, and fruits, than to learn them through mere sense impressions, or even through comparing coloured objects, as in the Montessori chromatic exercises. A study of the various kindergarten games and occupations would give an abundance of examples illustrative of the possibility of presenting knowledge in direct association with various types of constructive work. =A. Activity must be Directly Connected with Problem.=--It may be noted, however, that certain dangers associate themselves with these methods. One danger consists in the fact that, if care is not taken, the physical activity may not really involve the knowledge to be conveyed, but may be only very indirectly associated with it. Such a danger might occur in the use of the Montessori colour tablets for teaching tints and shades. In handling those, kindergarten children show a strong inclination to build flat forms with the tablets. Now unless these building exercises involve the distinguishing of the various tints and shades, the constructive activity will be likely to divert the attention of the pupil away from the colour problem which the tablets are supposed to set for the pupils. =B. Not too much Emphasis on Manual Skill.=--Again, in expressive exercises intended merely to impart new knowledge, it may happen that the teacher will lay too much stress on perfect form of expression. In these exercises, however, the purpose should be rather to enable the child to realize the ideas in his expressive actions. When, for example, a child, in learning such geographical forms as island, gulf, mountain, etc., uses sand, clay, or plasticine as a medium of expression, too much striving after accuracy of form in minor details may tend to draw the pupil's attention from the broader elements of knowledge to be mastered. In other words, it is the gaining of certain ideas, or knowledge, and not technical perfection, that is being aimed at in such expressive movements.