i 
C D 
firmative Figure before a Negaftive muft be diminiOi’d 
by an Unit. (2.) A negative Figure before an A^rma- 
tive, muO: be changed into its Compleinent to 10. 
(3.) A negative Figure before a Negative, muft be 
changed into its Complement to 9. All other Figures 
muft remain unchanged, and a Cypher is always to 
be underftood where there is no fignificant Figure. 
The fign of the Cypher is negledted ,♦ but where there 
is occafton to confider it, it is always fuppos’d the fame 
as the Sign of the following Figure. Thus the negati- 
vo-afJirmative Number 729586455982001730 is im- 
mediately reduc’d to 7 io585'5459779983 30,* and 
fo of all others. 
But on the contrary, common Numbers may be re- 
duced to negativo-affirmative Numbers a great variety 
of Ways, by fubftituting inftead of the Figures i, 2, 3, 
their refpetftive Values 19^187 i7m6> 
15,14,13,12,11, in any places at pleafure. But the 
moft ufelul Redutftion of this kind is what I call A Re- 
du^ton to fmall Figures^ which conftfts in throwing out 
all the large Figures, 9,8, 7,6, out of any given Num- 
ber, and introducing in their room the equivalent 
fmall Figures 11,12,13,14, refpedively. Thus 
181937462 may be reduc’d to 223143542, confifting 
only of fmall Figures. But this Redudion may be 
perform’d more readily by thefe Rules following. 
(i.) A fmall Figure before a large Figure muft be 
increafed by an Unit. Q2.4 A large Figure before a 
large Figure muft be changed into its negative Com- 
plement to 9. (3.4 A large Figure before a fmall Fi- 
gure muft be changed into its negative Complement 
to 10. Other Figures are not to be changed ; and y 
will be ambiguous, being to be efteemed either large 
or 
