PRACTICE. Practice is the method of finding the fourth term of a proportion in parts of the producing term. Operations in Practice are divided into those which are direct, and those which are indirect. Direct is when the required product is directly obtained from a given amount; Indirect Practice is when the product is obtained from an assumed amount. DIRECT PRACTICE. Case 1. When the given quantity is less, than the integer of the rate. * Rule. Take the same parts out of the given amount, that the given quantity is of the integer. EXAMPLE 1. To find the amount of 11 oz. of Tea, at 8 s. 6 d. per lb. In calculations of Practice, the statement of a question may be made in the same manner as in the calculations of the Rule of Three; and for the information of the young student the produc A rate is the two terms given in order to find a proportional result from another given quantity, and consequently answers to the first and second terms of the general mode of stating questions to be worked by the Rule of Three. An integral rate is therefore one in which the number of the first term would be expressed by unity, a per centage rate, by 100, &c. tion of the third term in parts of the first term may be first made, in order to show how the fourth term is to be obtained from the second. The reduction of the remainders from the pence may be made into either 4 ths or farthings, or 8 ths, that is half farthings, according to the nicety that the calculation may require; and when the parts are numerous or complicated, the remainders of the pence may be reduced into 10 ths or 100 ths; or the same may be done with the remainders of the farthings.-Thus, repeating the foregoing calculation, and showing the production of the third term in parts of the first, The amount of the 100 ths is 112, of which the 100-100 ths are carried forwards as 1 penny. EXERCISES. Find the amount of Ex. 1. 5 oz. at 8 s. per lb. 2.7 oz. at 4s. 6 d. lb. 3. 11 oz. at 5s. 6 d. 8. 17 lb. at 18 s. 3 d. 9. 23 lb. at 29 s. 6 d. per cwt. 10. 5 oz. 7 drs. at 4 s. 6 d. per lb. 11. 7 oz. 11 drs. at 3 s. 12. 13 oz. 13 drs. at 5 s. 7 d. per lb. 10 d. per lb. 13. 1 qr. 14 lb. at 14 s. 0 d. per cwt. per 1 114 per lb. per oz. Troy d. per oz. Troy per cwt. 2 8/3/2 Case 2. When the given quantity is greater than the integer of the rate. Rule. Multiply the given rate by the number of the integers, and take parts for the remaining quantity. EXAMPLE 2. To find the amount of 7 lb. 11 oz. at 8 s. 14 d. per lb. The remaining farthings are here reduced into 100 ths, and then divided; the amount, 112-100 ths, gives 1 farthing and 12 over. 1. 7 lb. 8 oz. at 11 d. per lb. E Product £0 6 101 PRACTICE. PART II. INDIRECT PRACTICE. Case 1. When the given quantity is a simple quantity. Rule. Assume the amount of the whole at an integral rate, and find the required amount in multiples or parts of the assumed amount. EXAMPLE 1. Find the amount of 117 yards at 4 s. 6 d. per yard. * In each of these Exercises the value may be assumed for the whole quantity at 1 d. per lb. or 1 s. per lb., and instead of putting it down in pence, it is shorter to EXERCISES CONTINUED. Assume the value at 1 s. each in the work, and at 1 d. each in Assume the value at £ 1 each in the work, and at 1 s. each in express it at once in shillings; as, instead of putting down 167 d., to put down 13 s. 11 d., mentally performing the division by 12. In the same manner when the value is assumed at 1s., the amount may be expressed in £, as in the first work of the above example. |