A MENTAL ARITHMETIC BY G. A. WENTWORTH, A.M. AUTHOR OF A SERIES OF TEXT-BOOKS IN MATHEMATICS BOSTON, U.S. A. I due T 118,95 € A HARVARD COLLEGE LIBRARY GEORGE ARTHUR PLIMPTON Entered according to Act of Congress, in the year 1895, by in the Office of the Librarian of Congress, at Washington. ALL RIGHTS RESERVED. Ginn Company MENTAL ARITHMETIC. CHAPTER I. INTEGRAL NUMBERS. Lesson 1. 1. Mary has 2 cents, and her mother gives her 1 more; how many cents has Mary then? 2. Charles had 2 marbles, and found 2 more in the schoolyard; how many marbles had he then? 3. Lucy found 3 eggs in a box and 3 more in the hay; how many eggs did she find in all? 4. John gave 3 pond-lilies to Hattie, and Arthur gave her 4; how many had she in all? 5. A boy has 5 rabbits in one pen and 2 in another; how many rabbits has he in both pens? 6. Mr. Brown had 4 horses, and bought 3 more; how many horses had he then? 7. Agnes has 4 spools of black thread and 5 spools of white; how many spools has she of both kinds? 8. James earned 6 dollars and afterwards 4 dollars more; how many dollars did he earn? 9. Mrs. Adams paid her grocer 5 dollars for sugar and 3 dollars for flour; how many dollars did she pay? Lesson 2. 1. Charles spent 7 cents for oranges and 3 cents for apples; how many cents did he spend in all ? 2. Anna has 6 red roses and 2 white roses; how many roses has she? 3. If there are 3 birds on one tree and 4 on another, how many birds are there on both trees? 4. A boy gets 2 stamps from his sister and 5 from his mother; how many stamps has he then? 5. If a man has 4 bay horses and 6 white horses, how many horses has he? 6. I can see 5 dogs in the street and 3 in the yard; how many dogs can I see? 7. If one boy makes 3 snow-men and another makes 6, how many snow-men do both boys make? 8. There are 2 boys and 7 girls in the front row; how many children are there in the front row? 9. I have 4 books on my table and 4 on the shelf; how many books have I? 10. A farmer has 3 cords of wood in one pile and 6 cords in another; how many cords has he? 11. If 6 inches of snow fall in the forenoon and 4 in the afternoon, how many inches fall in the day? 12. If a school has 2 men and 8 women for teacliers, how many teachers are there in the school? 13. There were 3 boys in the class, and 6 more entered; how many boys were there then? 14. One of my book-cases has 4 shelves and another has 5; how many shelves have both? 15. A boy spent 5 cents for an orange and 5 cents for three apples; how many cents did he spend? NOTE. 9 5 6 7 9 9 8 9 The Teacher should copy this Addition Table on the board, and require each pupil in turn to name the sums as the pointer touches the examples at random. The drill should be continued daily until every pupil is absolutely certain of the required answer. 7 3 8 8 3 4 421 6 2 2| 5 7 1 8 0 1 6 |