15. In example 11, how many times greater is the period to the left than the right-hand period? than the middle period? 16. The expenses of our government in one year were $1785687098. Separate this number into periods and read it. 17. Write four other numbers expressing billions. Write: 18. Ten thousand ten hundred two. 19. Six hundred millions six thousand six hundred. 20. Six billion sixty-six million ten thousand five. 21. Five hundred five billion ninety-eight thousand four hundred four. 22. Eight hundred million eight. 23. Six million five. 4. 4, 2, 6, 8 5. 3, 7, 1, 9 6. 5, 4, 6, 5 7. 2, 3, 8, 7 8. 5, 4, 1, 3 9. 6, 2, 4, 8 REVIEW OF ADDITION 1. Define addition; addends; plus; sum. 2. What must be observed in writing numbers to be added? 3. Add the numbers in examples 18-23 above. Add: 10. 30, 60, 10, 5 11. 22, 30, 20, 19 12. 25, 14, 25, 30 13. 18, 32, 30, 20 14. 50, 25, 25, 60 15. 40, 15, 60, 25 Give sums at sight: 16. 40, 60, 50 21. 42, 18, 7 26. 21, 14, 15 17. 65, 35, 40 22. 16, 32, 22 27. 48, 22, 69 18. 92, 28, 31 23. 72, 18, 35 28. 50, 65, 15 19. 86, 14, 25 24. 16, 24, 39 29. 25, 15, 23 20. 40, 15, 65 25. 87, 13, 25 30. 37, 62, 38 A large number of problems may be made from the following numbers. Add horizontally or vertically to a certain point; subtract the numbers in one column from those in a column to the right; or multiply the numbers in the last column by those in the first column, etc. In adding, notice convenient combinations. α 31. 594 32. 273 33. 634 34. 175 35. 439 36. 275 37. 684 38. 273 39. 619 40. 875 41. 267 42. 286 43. 394 44. 899 b 697 598 736 214 567 324 768 436 875 987 349 483 526 743 с 913 870 837 415 638 475 867 537 946 987 693 679 638 698 d 1043 1195 1375 2867 4298 5149 6238 2628 4153 1697 4278 4284 6953 8907 e 8697 7963 8674 3695 9369 6937 7245 8734 6928 7961 8639 5698 7293 5032 REVIEW OF SUBTRACTION 1. Define subtraction, minuend, subtrahend, remainder, minus, difference. 2. How may we test subtraction? Give differences at sight: 3. 43-28 9. 31 14 6. 86-43 4. 65-32 7. 71-18 8. 69-27 10. 26-19 5. 94-77 11. 37-24 15. When the minuend and the difference are given, how may the subtrahend be found? 37. 10000. Subtract in 3 minutes: 38. · 607008 448789 39. 16. When the difference and the subtrahend are given, how may the minuend be found? Take each number below from 1000: 17. 225 21. 216 25. 725 29. 715 33. 375 18. 314 22. 500 26. 946 30. 800 34. 814 19. 625 23. 499 27. 328 31. 125 35. 731 20. 374 24. 795 28. 613 32. 625 36. 656 Take each of the numbers in examples 17-36 from 40. 756008 398497 41. 180260 98775 12. 86-79 13. 96-93 14. 18-11 44. 800647900 98749897 45. 870009809 698058948 46. 906700983 798897497 REVIEW OF MULTIPLICATION 1. Show that multiplication is a short method of addition. 2. Define multiplication, multiplier, multiplicand, product, factors, an abstract number, a concrete number. 3. What kind of a number must the multiplier always be? 4. What does the multiplication sign show? Which term in multiplication is usually written before it? 5. At $2 a bushel, how much will 125 bushels of peaches cost? Which number is the multiplicand? Which one is the multiplier? 125 × $2 = ? How many times has the multiplicand $2 been taken? What is the product? Why is the product a concrete number? 6. Compare the product of 8 x 6 with the product of 6 x 8; the product of 2 × 14 with the product of 14 × 2. Either factor may be regarded as the multiplier. The multiplicand may be either concrete or abstract. When it is concrete, the product will have the same name as the multiplicand. The multiplier is always abstract. Hence, when a concrete multiplicand is for convenience used as multiplier, it must be regarded as abstract. Name two factors of: 7. 81; 125; 75; 64; 110; 108; 39; 72; 96; 80. 8. Multiply by 10, by 100, by 1000: (Do not use pencil.) 4; 8; 12; 15; 18; 25; 30; 35; 40; 50; 75. 9. State how the addition of one naught, two naughts, three naughts, etc., to the right of a number affects its value. State products: 10. 40 x 20 11. 20 × 20 12. 30 x 15 13. 50 x 20 14. 18 x 30 15. 30 × 70 16. 64 × 40 17. 70 × 28 18. 40 x 70 31. Find the amount of the following bills: 161 lb. butter at 18¢ a pound. 6 cans corn at 2 for 25¢. 32. 18 bu. potatoes at $0.65 a bushel. 25 bu. tomatoes at $0.55 a bushel. 27. 693 x $37.14 28. 245 x $64.59 29. 369 x $83.96 30. 248 x $39.81 3 boxes peaches at $1.75 a box. 15 qt. berries at 10 a quart. 33. Make a bill for 6 articles bought at a dry goods store. 34. Take the number 125, multiply it by 5, then this product by 5, and so on. Write only the products, not the multipliers. Continue for two minutes. How many successive products have been written? REVIEW OF DIVISION 1. Define division, dividend, divisor, quotient, remainder. 2. What is the sign of division? Division is indicated in three ways; thus, 155, 15, and 5)15. 3. In problem 2, which number is the dividend? which is the divisor? If the dividend and divisor are concrete, they must have the same The quotient is then abstract. Thus, $7 (divisor) is contained in $21 (dividend) 3 times (quotient). name. |