Number, as applied to objects, is one of the first properties perceived by the child; he/she intuitively distinguishes between one and more than one, and easily learns to add and subtract small numbers before he/she learns to read.

Addition and Subtraction, which are the converse of each other, are given in immediate connection; so also are Multiplication and Division. Each combination is thus presented in a variety of forms and may be fully committed to memory without wearying the learner.

Every lesson is accompanied by exercises and illustrations. In the exercises all the...