THE PRIMARY SCHOOL ARITHMETIC, DESIGNED FOR PRIMARY AND INTERMEDIATE SCHOOLS. BY DANIEL LEACH AND WILLIAM D. SWAN. PHILADELPHIA: THOMAS, COWPERTHWAIT, & CO. Sickner & Fields Entered according to Act of Congress, in the year 1850, by In the Clerk's Office of the District Court of the District of Massachusetts. STEREOTYPED AT THE BOSTON STEREOTYPE FOUNDRY. PREFACE. THIS book is designed for primary and intermediate schools, and is prepared to conduct the pupil from the simplest combinations of numbers, by easy and gradual steps, to others more difficult and complex. It has been the principal aim of the authors to make the combinations so easy, and to repeat them in so many different forms, as to indelibly impress them on the memory, and to render frequent explanation unnecessary. Nothing is attempted to be explained which can be readily comprehended; neither are there any difficulties presented for which the mind of the pupil (if properly taught) is not fully prepared. The pupil should be made to understand perfectly the first three lessons before proceeding to the fourth; and it should be vividly impressed upon his mind that all numbers are composed of units, and that each number contains one additional unit more than the preceding. To aid the pupil in forming a correct idea of numbers, the teacher may make use of any visible objects for counters, or may use marks on the slate or blackboard. Visible objects, however, should not be used except for the first few lessons, as it is very important |
