MENTAL EXERCISES. 1. If James should read 9 pages in his librarybook each day, how long would it take him to read 36 pages? ANS. 4 days. Why 4 days? Because, if he read 9 pages in 1 day, it will take him as many days to read 36 pages as 9 is contained times in 36; 9 in 36, 4 times, since 4 times 9 are 36. Therefore, he will read 36 pages in 4 days. 2. A class of 10 scholars performed 20 questions in arithmetic, at one recitation; how many questions was that apiece? Why? 3. How many classes, of 9 scholars each, can be formed from 27 scholars? From 18 scholars? From 45 scholars? Why? 4. At 10 shillings apiece, how many glass lamps can be bought for 30 shillings? For 50 shillings? For 40 shillings? Why? 5. When butter is 9 cents a pound, how many pounds can you buy for 54 cents? For 72 cents? For 63 cents? Why? Why? 6. How many shawls can I buy for 60 dollars, when they are worth 10 dollars apiece? How many for 80 dollars? For 70 dollars? For 90 dollars? For 110 dollars? For 100 dollars? 7. If you should travel 9 miles an would it take you to go 81 miles? 99 miles? How long to go 108 miles? hour, how long How long to go Why? 8. A class of 9 scholars presented their teacher with a book which cost 90 cents; how many cents apiece did the book cost them? Why? 9. How many times 10 in 120? Why? 11 in 11, 1 time 11 in 22, 2 times 11 in 33, 3 times 11 in 44, 4 times 11 in 55, 5 times 11 in 66, 6 times 12 in 12, 1 time 12 in 24, 2 times 12 in 36, 3 times 12 in 48, 4 times 12 in 60, 5 times 12 in 72, 6 times 11 in 99, 9 times 11 in 110, 10 times 11 in 121, 11 times 11 in 132, 12 times 12 in 84, 7 times 12 in 96, 8 times 12 in 108, 9 times 12 in 120, 10 times 12 in 132, 11 times 12 in 144, 12 times MENTAL EXERCISES. 1. Here are 22 little girls in this beautiful arbor; if 11 can sit on one seat, how many seats will accom modate the whole? ANS. 2 seats. Why 2 seats? Because, if 11 girls can sit on 1. seat, 22 girls will require as many seats as 11 is contained times in 22; 11 in 22, 2 times, since 2 times 11 are 22. Therefore, the 22 girls will require 2 seats. 2. If you divide 24 grapes equally between 12 of these girls, how many grapes will each one receive? Why? How many, if you divide 36 equally between them? Why? 3. At 11 cents a yard, how many yards of edging can you buy for 33 cents? For 55 cents? For 44 cents? Why? 4. In one year there are 12 calendar months; how many years in 48 calendar months? In 72? In 60? Why? 5. At the rate of 11 miles an hour, how long will it take a man to travel 66 miles? How long to travel 88 miles? 77 miles? Why? 6. When satin is 12 shillings a yard, how many yards can be bought for 84 shillings? For 108 shillings? For 96 shillings? Why? 7. George bought a drawing-book for 11 cents; how many could he buy for 99 cents? For 121 cents? For 110 cents? Why? 8. How many cows, at 12 dollars apiece, can be bought for 120 dollars? For 132 dollars? For 144 dollars? Why? 9. A merchant bought a piece of silk, containing 132 yards; how many dresses can be made from it, allowing 11 yards for a dress? Why? 1. 2 in 2. 2 in 3. 4. 5. 6. 7. 8. 11. 2 in 6, how many times? 8, how many times? 12, how many times? 2 in 10, how many times? 2 in 14, how many times? 2 in 18, how many times? 2 in 16, how many times? 2 in 22, how many times? 9. 2 in 20, how many times? 10. 2 in 24, how many times? 3 in 15, how many times? 3 in 12, how many times? 3 in 18, how many times? 14. 3 in 24, how many times? 15. 3 in 21, how many times? 16. 3 in 27, how many times? 17. 3 in 33, how many times? 18. 3 in 30, how many times? 19. 3 in 36, how many times ? 4 in 24, how many times? 4 in 28, how many times? 4 in 36, how many times? 12. 13. 20. 21. 22. 23. 4 in 32, how many times? 24. 4 in 44, how many times? 25: 4 in 40, how many times? 26. 4 in 48, how many times ? 27. 5 in 25, how many times? 28. 5 in 35, how many times? 29. 5 in 30, how many times? 30. 5 in 45, how many times? 31. 5 in 40, how many times? |