MENTAL ARITHMETIC CONTAINING THE PRINCIPLES OF ARITHMETIC WITH NUMEROUS PROBLEMS FOR ORAL ANALYSIS AND SOLUTION ALBERT N. RAUB, Ph.D. PRESIDENT OF DELAWARE COLLEGE, AND AUTHOR OF “SCHOOL MANAGEMENT," ENGLISH AND AMERICAN LITERATURE." HARVARD COLLEAE LIBRARY GIO.GE ARTHUR PLITIPTON JANUARY 25, 1321 Copyright, 1894 by ALBERT N. RAUB WER. MEN. ARITH. PREFACE. The educational public have become so accustomed to the term mental arithmetic, and the title has become so distinctive, that it would probably be unwise to call the exercises prepared for a book of this kind by their proper name—oral arithmetic. Mental Arithmetic is therefore used as the name of the book, because this title has become most familiar to both teacher and pupil. The author has tried to make this work not only progressive and practical in its character, but also to adapt it to the wants of those who believe that oral and written arithmetic should be taught in conjunction, the mental or oral arithmetic being made to serve the purpose of developing the principles of the science by a class of problems simpler than are usually found in the written arithmetic, where the help of pen or pencil is an excuse for their presence. Much of the opposition which once existed against the study of mental arithmetic arose partly because the subject was made too difficult, and partly because there was no visible connection, as ordinarily taught, between the oral and the written process. In order to overcome these objections all ambiguous or mere puzzle problems have been discarded, and special efforts have been made to develop the principles of the science in harmony with the order and methods found in works on arithmetic where both the oral and the written process are used, but giving a greater number and variety of problems for oral solution than could profitably be given in a book in which both processes are combined. MENTAL ARITHMETIC. ADDITION. I. 1. A boy has 1 right eye and 1 left eye; how many eyes has he? 2. If I have 2 apples in one hand and 1 apple in the other, how many apples have I ? 3. Mary has 2 books and her sister has 2; how many have they together ? 4. Mary had 3 cents and found 1; how many had she then ? 5. A boy had 3 dollars and earned 2 dollars more; how many dollars had he then ? 6. James found 2 apples and George found 3; how many did they both find ? 7. Tabby caught 3 mice and Tom caught 3; how many did they both catch ? 8. A pencil cost 4 cents, and some pens 3 cents ; how much did they both cost ? 9. If a boy has 5 cents and his sister has 2 cents, how many cents have they together ? 10. How many cents are 6 cents and 1 cent ? 11. A man earned 4 dollars on Monday and 4 dollars on Tuesday; how much did he earn in the two days ? |