4. Find the least common denominator (see § 96), and add the fractions,,, and . Ans. 5. Find the least common denominator and add 6 3 , and 3. 12 59 120 Ans. 196 NOTE. § 105. When there are mixed numbers, instead of reducing them to improper fractions we may add the whole numbers and the fractional parts separately, and then add their sums. 6. Add 194, 63, and 4 together. § 106. When the fractions are of different denominations. RULE. Then Reduce the fractions to the same denomination. reduce all the fractions to a common denominator, and then add them as in Case I. EXAMPLES. 1. Add of a £ to % of a shilling. of a £3 of 20-40 of a shilling: Then, 40+5=240+15=255s=85s=14s 2d. Or, the of a shilling might have been reduced to the fraction of a £ thus, of 2010 of a £= of a £. 48 of a £: which being re Then, +4+3 duced by § 100, gives 14s 2d. of a yard to 5 of an inch. 2. Add 3. Add together. Ans. Ans. 14s. 2d. yds. or 14in. of a week, of a day, and of an hour Ans. da. hr. 4. Add of a cwt., 85lb. and 3oz. together. Ans. 2qr. 171b. 1oz. 5. Add 11 miles, furlongs, and 30 rods together. Ans. 1m. 3 fur. 18rd. NOTE. The value of each of the fractions may be found separately, and their several values then added. 6. Add of a year, of a week, and of a day together. 7. Add of a yard, & of a foot, and of a mile together. Ans. yd. ft. in. 8. Add of a cut., 42 of a lb. 13oz. and of a cut. 6lb. together. Ans. 1cwt. 1qr. 27lb. 13oz. Q. How do you add fractions of different denominations? What is the second method? SUBTRACTION OF VULGAR FRACTIONS. § 107. It has been shown (see § 102), that before fractions can be added together, they must be reduced to the same unit and to a common denominator. The same reductions must be made before subtraction. SUBTRACTION of Vulgar Fractions teaches how to take a less fraction from a greater. Q. Can one-third of a shilling be subtracted from one-third of a £ without reduction? Can one-fourth of a shilling be subtracted from one-fifth of a shilling? What reductions are necessary before sub. traction? What is subtraction? CASE I. § 108. When the fractions are of the same denomination and have a common denominator. RULE. Subtract the less numerator from the greater and place the difference over the common denominator. EXAMPLES. 1. What is the difference between and ? Here we have 5-3=2: hence, the difference. § 109. When the fractions are of the same denomination, but have different denominators. RULE. Reduce mixed numbers to improper fractions, compound fractions to simple ones, and all the fractions to a common denominator: then subtract them as in Case I. EXAMPLES. 1. What is the difference between 3 and ? 5 5 Here, ---3-3-3 answer. Q. How do you subtract fractions which have the same unit but different denominators? What is the difference between one-half and one-third? 2. What is the difference between 12 of and 2? Ans. 12. 3. What is the difference between 2 of a £, and of a £? 1 4. From of 6, take 19 of 3. 5. From of 3 of 7, take 3 of 5. G. From 371, take 35 of 3. CASE III. 3 Ans. £ S. § 110. When the fractions are of different denominations. RULE. Reduce the fractions to the same denomination: then reduce them to a common denominator, after which subtract as in Case I. EXAMPLES. 1. What is the difference between of a £, and of a shilling? of a shilling of 20 of a £. Then, -638-36-38 of a £=9s 8d. 1 30 2 60 60 60 Q. How do you subtract fractions which are of different denomi nations? 2. What is the difference between of a day and of a second? Ans. 11hr. 59m. 59 sec. 3. What is the difference between 6 of a rod and of an inch? Ans. 10 ft. 114in. 4. From 12 of a lb. troy weight, take of an ounce. Ans. 5. What is the difference between of a hogshead, Ans. 16gal. 2qt. 1pt. 37gi. and of a quart? 9 6. From of a £ take of a shilling? Ans. s. d. 7. From oz. take pwt. 8. From 43cwt. take 4lb. Ans. 11pwt. 3gr. Ans. 4cwt. 1qr. 15lb. 1oz. 93}dr. MULTIPLICATION OF FRACTIONS. For 4? § 111. John gave of a cent for an apple. How much must he give for 2 apples? For 3 apples? For 5? For 6? For 7? For 8? For 9? Charles gave of a cent for a peach? must he give for 2 peaches? For 3? For 4? For 6? EXAMPLES. 1. Multiply the fraction by 4. When it is required to multiply a fraction by a whole number, it is required to increase the fraction as many times as there are units in the multiplier, which may be done by multiplying the numerator How much OPERATION. x4===2}; or by dividing the denominator by 4, we have ×4=42}. (see § 80), or by dividing the denominator (see § 83). CASE I. § 112. To multiply a fraction by a whole number. RULE. Multiply the numerator, or divide the denominator by the whole number. Q. How do you multiply a fraction by a whole number? § 113. NOTE. When we multiply by a fraction it is required to repeat the multiplicand as many times as there are units in the fraction. 3 For example, to multiply 8 by 3 is to repeat 8, 2 times; that is, to take 2 of 8, which is 6. Hence, when the multiplier is less than 1 we do not take the whole of the multiplicand, but only such a part of it as the fraction is of unity. For example, if the multiplier be one-half of unity, the product will be half the multiplicand: if the multiplier be of unity, the product will be one-third of the multiplicand. Hence, to multiply by a proper fraction does not imply increase, as in the multiplication of whole numbers. Q. What is required when we multiply by a fraction? What is the product of 8 multiplied by one-half? By one-fourth? By oneeighth? By three-halves? By six-halves? What is the product of 9 multiplied by one-half? By one-third? By one-sixth? By one-ninth? When the multiplier is less than 1, how much of the multiplicand is taken? Does the multiplication by a proper fraction imply increase ? product divided by 7, a result which is obtained by multiplying the numerators and denominators together. Hence, we have the following RULE. Reduce all the mixed numbers to improper fractions, and all compound fractions to simple ones: then multiply the |