Also, ·23 of a day is ·23 × 24 in hours, or 5ʰ·52; and ·52 of an hour is ·52 × 60 in minutes, or 3ᵐ·2; and ·2 of a minute is ·2 × 60 in seconds, or 12ˢ; whence ·23 of a day is 5ʰ 31ᵐ 12ˢ. Again, suppose it required to find what part of a pound 6_s_. 8_d_. is. Since 6_s._ 8_d._ is 80 pence, and since the whole pound contains 20 × 12 or 240 pence, 6_s._ 8_d._ is made by dividing the pound into 240 parts, and taking 80 of them. It is therefore £⁸⁰/₂₄₀ (107), but ⁸⁰/₂₄₀ = ⅓ (108); therefore, 6_s._ 8_d._ = £⅓. EXERCISES. ⅖ of a day is 9ʰ 36ᵐ ·12841 of a day 3ʰ 4ᵐ 54ᔆ·624[45] ·257 of a cwt. 28ˡᵇˢ 12ᵒᶻ 8ᵈʳ·704 £·14936 2ˢ 11ᵈ 3ᶠ·3856 [45] When a decimal follows a whole number, the decimal is always of the same unit as the whole number. Thus, 5ᔆ·5 is five _seconds_ and five-tenths of a _second_. Thus, 0ᔆ·5 means five-tenths of a second; 0ʰ·3, three-tenths of an hour. 221, 222. I have thought it best to refer the mode of converting shillings, pence, and farthings into decimals of a pound to the Appendix (See Appendix _On Decimal Money_). I should strongly recommend the reader to make himself perfectly familiar with the modes given in that Appendix. To prevent the subsequent sections from being altered in their numbering, I have numbered this paragraph as above. 223. The rule of addition[46] of two compound quantities of the same sort will be evident from the following example. Suppose it required to add £192. 14. 2½ to £64. 13. 11¾. The sum of these two is the whole of that which arises from adding their several parts. Now ¾_d._ + ½_d._ = ⁵/₄_d._ = £0 . 0 . 1¼ (219) 11_d._ + 2_d._ = 13_d._ = 0 . 1 . 1 13_s._ + 14_s._ = 27_s._ = 1 . 7 . 0 £64 + £192 = 256 . 0 . 0 ----------- The sum of all of which is £257. 8 . 2¼ This may be done at once, and written as follows: £192 . 14 . 2½ 64 . 13 . 11¾ ---------------- £257 . 8 . 2¼ [46] Before reading this article and the next, articles (29) and (42) should be read again carefully. Begin by adding together the farthings, and reduce the result to pence and farthings. Set down the last only, carry the first to the line of pence, and add the pence in both lines to it. Reduce the sum to shillings and pence; set down the last only, and carry the first to the line of shillings, and so on. The same method must be followed when the quantities are of any other sort; and if the tables be kept in memory, the process will be easy. 224. SUBTRACTION is performed on the same principle as in (40), namely, that the difference of two quantities is not altered by adding the same quantity to both. Suppose it required to subtract £19 . 13. 10¾ from £24. 5. 7½. Write these quantities under one another thus: £24. 5. 7½ 19. 13. 10¾