A. Multiplying by the 3 tens, that is, 30 units, gives a produc! 10 times greater than if the 3 tens were 3 units; hence the 5 must be placed in the tens' place To explain why you add the two products together. 4. The number of days in 6 years. Q. What does multiplying 365 by 3 tens give? A. As the 3 (tens) are 30 units, multiplying by 30 wil!, of course, give the number of days in 30 years. Q. Why, then, do you add these two products together? 1. To get the whole number of days in 30 and 6 years, that is, in 36 years. From this example we derive the following RULE. Q. How do you write the numbers down, and multiply? Q. Where do you write the first figure in each product? Q. How do you proceed next? A. Add all the products together as they stand. More Exercises for the Slate. 2. What will 315 bushels of rye cost, at 42 cents a bushel? A. 13230 cts. 3. There are 63 gallons in a hogshead; how many gallons are there in 25 hogsheads? A. 1575 gallons. 4. What will 426 gallons of molasses cost, at 46 cents a gallon? A. 19596 cts. 5. If 363 men can do a piece of work in 137 days, how long will it take one man to do the same? A. 49731 days. 6. What will 234 barrels of beef come to, at 15 dollars a barrel? At 13 dollars a barrel? A. 6552 dollars. 7. If a man receive 256 cents for one day's work, how many cents will he receive, at that rate, for 17 days? For 29 days? A. 11776 cents. For 116 days? For 105 days? 4.56576. 8. If the stage runs 9 miles an hour, how many miles will it run, at that rate, in 12 hours? In 19 hours? A. 279 miles. In 25 hours? In 36 hours? A. 549 miles. 9. If a man save 161 dollars in a year, how much will it amount to in 19 years? In 35 years? A. 8694 dollars. 10. Multiply 62123 by 13. 11. Multiply 35432 by 14; by 15. 12. Multiply 65217 by 16; by 17. 13. Multiply 207812 by 19; by 21. 14. Multiply 207812 by 25; by 35. A. 807599. A. 1027528. A. 2152161. A. 8312480. 15. Multiply 32100421 by 65; by 85. 16. Multiply 32100421 by 27; by 33. A. 4815063150. A. 1926025260 17. Write down one thousand, multiply it by 25, add five thousand to the product, subtract twenty-nine thousand nine hundred and ninety-nine from the amount, and see if the remainder be 1. ¶ XII. WHEN THE MULTIPLIER IS 10, 100, 1000, &c. Q. How many are 10 times 5? Now, if we annex a cipher to the 5, thus, 50, it will produce the same effect: why is this? A. Because, by annexing a cipher to 5, the 5 is removed to the tens' place; hence the value is increased 10 times. Q. What effect would two ciphers have, or three ciphers, &c.? A. Two ciphers would remove any figure two places towards the left, and of course increase it 100 times, and so on for 1000, &c. RULE. Q. What, then, appears to be the rule? A. Annex to the multiplicand all the ciphers in the multiplier. Exercises for the Slate. 1. What will 36 bushels of rye cost, at 100 cents a bushel? A. 3600 cents. 2. What will 100 bushels of salt cost, at 87 cents a bushel? What will 1000 bushels ? What will 10000 bushels? What > will 10 bushels? A. 966570 cents. 3. Multiply 8978 by 10; by 100; by 1000; by 10000; by 100000; by 1000000. A. 9975545580. ¶ XIII. When there are CIPHERS AT THE RIGHT HAND OF EITHER OR BOTH the FACTORS. RULE. Q. From the illustrations given, ¶ XII., how does it appear that we can multiply? A. Multiply without the ciphers first, and annex them to the product. Exercises for the Slate. (1.) Multiplicand, 63500 50 Q. How do you get the 3 ciphers in the product? A. There are 2 at the right of the multiplicand, and 1 at the 3175000 right of the multiplier, making 3. The Key contains the entire work of the six following examples; and similar aid is afforded the teacher in other parts of this treatise, when the process of solution is long and tedious. 2. Multiply 62123000 by 130000. A. 8075990000000. A. 9070592000000. A. 4652744481231000000 Q. How many are 5 times 8? 7 times 9? 12 times 12? Q. What are these products, 40, 63, 144, called ? A. Composite Numbers. Q. What are the multiplying numbers, 5 and 8, 7 and 9, 12 and 12, called ? A. The Component Parts. Q. What are the component parts of 36? Of 72? Of 100? Of 27? Of 15? Of 35? Of 132 Of 144 ? Q. What, then, is the product of any two numbers called? A. A Composite Number. 1. What will 14 barrels of flour cost, at 8 dollars a barrel? OPERATION 8 dollars. 7 barrels. 56 dollars. 2 times 7 are 14. 112 dollars, Ans. Q. What does multiplying 8 dollars by 7 barrels give? A. The price of 7 barrels at 8 dollars a barrel, making 56 dollars. Q. How much more will 14 barrels cost than 7 barrels ? A. 2 times as much as 7, that is, 2 times 56, making 112 dollars. RULE. Q. How, then, would you begin to multiply? More Exercises for the Slate. 2. What will 36 hundred weight of sugar cost, at 29 dollars a hundred? A. 1044 dollars. 3. Multiply 3065428 by 35. 4. Multiply 4078945 by 96. 5. Multiply 18934 by 108. 6. Multiply 45678 by 144. A. 107289980. A. 391578720. A. 2044872. A. 6577632. SIMPLE DIVISION. ¶ XV. 1. If you divide 12 apples equally between two boys, how many will each have? How many times 2 in 12, then? Why? A. Because 2 times 6 are 12? 2. How many oranges, at 8 cents apiece, can you buy for 48 cents? For 96 cents? How many times 8 in 48? 8 in 96? Why? 3. A man bought 8 lemons for 80 cents; how much did he give apiece? How many times 8 in 80? Why, or proof? 4. How many gallons of brandy, at 3 dollars a gallon, can be bought for 36 dollars? For 60 dollars? For 90 dollars? For 300 dollars? Why? 5. Four boys found a bag containing 48 silver dollars; how many will they have apiece, if it be divided equally? 6. When oranges are 2 cents apiece, how many will 8 cents buy? Will 16 cents buy? Will 32 cents? Will 36 cents? Will 48 cents? Will 100 cents? 7. If you pay 9 cents for one pound of sugar, how many pounds can you buy for 45 cents? For 54 cents? For 108 cents? 8. How much is one half () of 4? Of 8? Of 16? Of 20? Of 24? Of 30? Of 100? Of 200? 9. Harry had 16 apples, and gave one half (3) of them to Thomas; how many did Thomas receive? 10. How much is one third (3) of 6? Of 24? Of 30? Of 36? 11. How much is one half (1) of 8? One third (3) of 24 ? One fourth (1) of 16? One fifth (†) of 35? One sixth (†) of 24? One seventh (4) of 35? One eighth () of 56? One ninth (3) of 108: One twelfth (12) of 144? 12. How many times 4 in 40? 3 in 60? 5 in 100? 6 in 1200? 8 in 480? Q. What is this method of finding how many times one number is contained in another, ur of dividing a number into equal parts, called ? A. Division. Q. What is this method of finding how many times one number is contained in another of only one name, or denomination, called? A. Simple Division. Q. What is the number given to divide by called? A. The Divisor. Q. What is the number to be divided called? A. The Dividend., Q. What is the number of times that the divisor is contained in the dividend called? A. The Quotient. Q. What is that which is sometimes left after dividing, or after the operation is performed, called? A. The Remainder, which must always be less than the Divisor. Q. Of what name, or denomination, is the remainder? A. The same as the Dividend. Q. If your dividend, for instance, be ounces, what will your remainder be? A. Ounces. Q. How many times 4 in 40? and why? Q. From this example, what does Division appear to be the oppo site of? A. Multiplication. Q. James, having 12 oranges, was desirous of divieling them equally among his 4 little sisters, and, in order to do this, he handed them at first one apiece; how many had he left? Q. When he handed them another apiece, how many had he left? Q. When he handed them one more apiece, how many had he left? 1st time he had 12 oranges. One to each makes 4 8 left. One to each makes 4 2d time he had 4 left. 4 O left. 3d time he had Q. From these illustrations, how does it appear that a number may be divided into equal parts? A. By Subtraction. |