Ex. 10. 21. The sign + (plus), connecting two numbers, shows that they are to be added together. (1) 171407+90892+78832+2600+102777. (2) 79213+2856+7915+27384+68005+729. (3) 758+22727+4375+4375+85+68+9127+43761. Ex. 11. 22. The sign means equal to, thus 5+6+7=18 signifies that the sum of 5, 6, and 7, is 18. (1) What is the sum of two hundred and eighty-eight thousand, and five hundred and seventy-six thousand. (2) Write down seven nines, and add them together. (3) Write down eleven eighteens, and add them together. Write down fourteen twenty-fives, and add them to gether. (5) Find the sum of three thirty-nines, and six fortyeights. (6) Find the sum of six seventeens, seven eighteens, and eight nineteens. (7) In walking to school, Tom has taken 215 steps, Harry 195 steps, and Alfred 368 steps. How many steps did they take altogether? (8) If Alice and Mary have seventeen flowers each, and their brother have twenty-nine; how many flowers will they have in all? (9) How many pence are required to pay 18 pence for butter, 25 for tea, 33 for sugar, and 7 for rice? (10) I am twenty-eight years old, and my uncle is fourteen years older. How old will my uncle be when I am as old as he is? (11) The first of 3 flocks of sheep contains two hundred and eighty-five; the 2nd, ninety-six; the 3rd, seven hundred and eighty-seven. How many sheep are there in all? (12) A man walked forty miles on Monday, twenty-seven on Tuesday, thirty-six on Wednesday, eleven on Thursday, nine on Friday, and eight on Saturday. If he receives a penny for each mile he walks, how many pence will he receive? (13) In a school there are five classes; the fifth class has twenty-two boys; the fourth, nine more than the fifth; the third, seven more than the fifth; the second, three more than the third; and the first, as many as the fifth and second together. How many boys are there in the school? (14) What difference, if any, is there between 5 and 05? (15) A gentleman left to his daughter seven thousand six hundred and fifty pounds, and to each of his two sons one thousand three hundred and fifty pounds more than to the daughter. What sum did the gentleman leave altogether? (16) Find the sum of eighteen thousand nine hundred and six, seven hundred and nine thousand and eighty-five, and thirteen thousand seven hundred and twelve. (17) Mr. Jones has 168 roods of land, Mr. Walker and Mr. Chase have each 26 roods more. How many roods have the three altogether? Additional Exercises. Other addition sums may be formed from the following table. If these sums are taken in pairs, so that when one sum is taken from Part I. another sum is formed of the corresponding figures in Part II., the answers may be easily verified. If the two answers be added together, all the figures of the sum will be nines, except the two extremes, and the sum of the extremes will be nine. For example, make two sums of the figures in LKJI and in lines w x y z, (these figures are marked with dotted lines in the table), the answer to the first is 24376, and to the second 15620. The sum of these numbers is 39996. Similarly, if any number of pairs of sums be worked and all the answers added, all the figures in the sum will be nines except the extremes, and the sum of the extremes will be nine. The figures may be taken from Part I. of the table in any order, provided the corresponding figures in Part II. form the accompanying sum. In this way 200,000 sums may be formed and their answers verified. Simple Subtraction." 23. Subtraction is the process by which we find the number remaining when a smaller number is taken from a greater. 24. The number remaining is called the REMAINDER or the difference. 25. Case I.-When each figure in the lower line is less than the figure above it. RULE.-Write the less number under the greater so that units are under units, tens under tens, and so on. Draw a line under and subtract each figure of the lower number from the figure above it, writing the remainder below the line. 26. Case II. When any figure in the lower number exceeds the figure above it. RULE. Add ten to the upper figure, subtract the lower, and put down the remainder. Add one to the next figure in the lower line, and proceed as before. 27. The rule in this case depends on the fact that, if two numbers are increased by the same amount, their difference is not altered. |