Willsfords arithmetick, naturall, and artificiall: or, decimalls. Containing the science of numbers, digested in three books. Made compendious and facile for all ingenious capacities, viz: merchants, citizens, sea-men, accomptants, &c. Together with the theorie and practice united in a sympathetical proportion betwixt lines and numbers, in their quantitites and qualities, as in respect of form, figure, magnitude and affection: demonstrated by geometrie, illustrated by calculations, and confirmed with variety of examples in every species. / By Thomas Willsford, Gent.

Sect. I. Chap. III. Subtraction of Decimalls with integers and fractions commixt together.

If severall

				L.
1	− 9260417	2	20	275
	− 3989583		8	2875
Re.	− 5270834	Re.	11	9875
	L.			L.
3	40	1666667	4	100	—
	− 325		− 008333
Re.	39	8416667	Re.	99	991667

summes be given to be subtracted, reduce thē unto To∣talls, and place them according to their degrees, as in the last Chapter, and then sub∣tract the lesser number from the greater, and if the Decimalls are unequall, that defect may be supplied with points, or suppose cyphers to be annext unto them, in all things else (except their degrees) it dif∣fers nothing from the subtraction of whole num∣bers, as by these 4 Examples shall be made evident: in the first is propounded 18 s. 6 d. 1 q. from whence 7 s. 11 d. 3 q. is to be taken in Decimalls, which to finde I have shewn already, yet for your ease one more shall be inscribed, and first for 18 s. the vulgar fraction is 9/10 the Decimall − 9 then 6 d. is ½ of 1/20 that is 1/40 the artificiall number − 025, then 1 q. is ¼ of 1/12 of 1/20 that is 1/960 the Decimall − 0010417. the totall −9260417: and in this manner you will finde the second number to be − 3989583 which taken from the former, there will remaine − 5270834.

which is the Decimall of 10 s 6 d. ½. the true re∣mainder of the vulgar numbers if subtracted. In the second Table 8 L. 5 s. 9 d is given to be subtracted from 20 L 5 s. 6 d. the Decimall of 5 s. is − 25 of 6 d. − 025 the summe is 20 L 275. the totall of 5 s. 9 d. is − 2875, so the lesser summe is 8 L. − 2875 the dif∣ference is 11 L. − 9875 according to the Table, which is 19 s. 9 d. The third Table is 6 s. 6 d. to be subtracted from 40 L 3 s. 4 d. the summe of the De∣cimalls answering 3 s. 4 d. is − 1666667 − the Deci∣malls belonging to 6 s. 6 d. is − 325 to which annex cyphers or make points as in the Table, and subtract them according to vulgar or Naturall Arithmetick, the difference is 39 L. and this Decimall − 8416667 equall to 16 s. 10 d. The fourth and last Example is of 100 L. from whence 2 d. is to be deducted, whose Decimall is − 008333: suppose cyphers or points re∣presenting their places, and subtract the Decimall, as in the Table, where you will finde the remainder 99 L. − 991667 the Decimall of 19 s. 10 d. answer∣ing the truth and your expectation too. This Chap: is tried by the last, and that prov'd by this, as by subtraction in Naturall Arithmetick, to which I re∣ferre you for the form and reason, and for the pra∣ctick part to this Chapter, in 4 Examples.