2 times 3 times MULTIPLICATION TABLE. 4 times 5 times 6 times 7 times 1 are 2 1 are 3 1 are 4 1 are 5 1 are 6 1 are 7 *The above table should be thoroughly committed to memory before the learner proceeds further. NOTE. This table should be written with chalk upon the black board, and recited in concert by the whole class, first from top to bottom, then from bottom to the top of the column. The exercise should be continued from time to time, taking one column for a lesson, until the whole is thoroughly learned. The best way to determine whether a column is thoroughly learned by the pupils, is for the teacher to rub out the products, and then with a rod to point promiscuously in the left-hand column, and if the class can keep up a good concert whilst going over the numbers thus, it may be taken for granted that the lesson is pretty well learned. C 13. What will 9 pounds of sugar cost at 13 cents a pound? 14. What cost 12 yards of cloth at 7 dollars a yard? Why? 15. If a man can earn 13 dollars a month; how much can he earn in 8 months? 16. What will 16 oranges cost at 3 cents a piece? Why? 17. In one gallon there are 8 pints; how many pints in 13 gallons? Why? 18. Which is the greater 8 times 13, or 13 times 8? 19. If a you read 14 pages in a day; how many pages could you read, at that rate, in 9 days? Why? 20. How much will 16 melons cost at 9 cents a-piece? Why? 21. If a man can walk 24 miles in one day, how many miles can he walk in 6 days? Why? 22. What will 12 pounds of butter cost at 18 cents a pound? 23. What are 8 dozen eggs worth at 15 cents a dozen? Why? 24. There are 8 quarts in a peck; how many quarts in 14 pecks? 25. If one ton of hay cost 17 dollars what will 6 tons cost? Why? 26. If a pound of honey cost 14 cents, what will 7 pounds cost? Why? 27. If a steamboat will go 13 miles in one hour, how far will it go in 12 hours? Why? 28. If a labourer can earn 16 dollars in a month, how much can he earn in 11 months? Why? 29. There are 4 gills in a pint, and 8 pints in a gallon; how many gills in 2 gallons? 30. There are 12 inches in one foot; how many inches in 9 feet? Why? 31. There are 1760 yards in one mile; how many yards in 7 miles, one of these numbers being greater than any in the multiplication table, we must use the slate and multiply one figure at a time. Thus, Here we say, 7 times 0 make 0, then 7 Yds. times 6 make 42, that is, 42 tens, which is 1760 equal to 4 hundred and 2 tens, put down the 72 under the 6 tens, and then say, 7 times 7 12320 make 49 hundreds, and 4 hundreds make 53 hundreds, 5 thousands and 3 hundreds, put down the 3 hundreds under the 7 hundreds, and then say, 7 times 1 make 7 thousands, and 5 thousands make 12 thousands. By multiplication we ascertain what a number amounts to when repeated a given number of times; thus, 3 times 4 make 12, that is, 4 repeated 3 times make 12. The number to be multiplied is called the multiplicand, the number we multiply by is called the multiplier, the result of multiplication is called the product. The multiplier and multiplicand are also called factors, or either of them a factor. RULE FOR MULTIPLICATION. Write the multiplier under the multiplicand, placing units under units, tens under tens, &c. Commence at the right hand and multiply each figure in the multiplicand separately, and place the right hand figure of each product under the figure in the multiplicand from which it arose, and carry the left hand figure as in addition. If there is more than one figure in the multiplier, multiply by each figure separately, and write its product in a separate line, placing the right hand figure of each product directly under the figure by which you multiply, after which add to them the several products, the sum will be the required product. 3. Suppose 674 be the multiplicand and 24 the multiplier, what is the product? 674 This character = 2696 1348 Product 16176 signifies equal, as 1 +addition, as 4+12=16. 9. What will 96 barrels of flour cost at 7 dollars a barrel? Ans. 662 dollars. Why? Say, if it takes 7 dollars to buy one barrel, the whole cost will be seven times as many dollars as there are barrels. 10. There are 24 hours in one day; how many hours in 7 days? Ans. 168 hours. Why? Say, if there are 24 hours in one day, in 7 days there will be 7 times 24 hours. 11. Suppose 4673 be one factor, and 3764 another; what is the product? PROOF OF MULTIPLICATION. Add together all the figures in the product, and observe the number of 9s contained in the sum, and put down the excess; do the same with each factor, then multiply together the excess of the factors and cast out the nines from the product. If the excess in this case be the same as that in the first product the work may be considered right. It is proper to observe, however, that there is a possibility of an error being in the work, though it proves correct by this process, but as this error must be just 9, in the units, tens, or hundreds, &c., it is not likely to occur very often. 12. Multiply 7438 ×4 by 3652 3652 x7 14876 28 37190 44628 22314 The sum of the figures in the multiplicand is 22, this makes two nines, and an excess of 4, in the multiplier there is one nine, and an excess of 7, their product is 28= three nines, and an excess of 1, the same as that in the product. Counting the nines in the product we say, the 7 and 2 make 9, then 6 and 3 make 9, we have yet 1, 5, 7, and 6, these make two nines, and an excess of 1. 27163576 |