( 89 ) 
Again: From 9312 
Take 7434 
Sum 1878 
If you were totally ignorant of the firft 
rules of Arithmetic, you would not imme- 
diately difcover by what means 4 could be 
fubtrafted from 2, or 3 from i, or again 4 
from 3. But, if in your mind, you take 
ten from the next figure and add it to the 
2, you can then fubtracl: the 4 from 12 and 
the remainder will be 8. You now pro- 
ceed to the next figure 3, which you are to 
fubtracl: from the i above it, but as you 
have already taken 10 from this i, which 
flanding in the ten's place is one ten, it be- 
comes a o ; therefore you are to fubtracl: 3 
from o: this being impoflible, you again 
take ten from the next figure and fubtracl:- 
ing 3 from ten, you put down 7. You are 
now to take 4 from the 3 above j but this 3 is, 
in fact, only 2, for the fame reafon that the 
1 became a o ; 4 cannot be fubtracled from 
2 j I therefore take ten from the 9000, and 
fay 4 from 12, there remains 8. But you 
are to obferve, though I call it taking ten 
from the next figure, that, when from the 
3 I took 10, in facl: I took 1005 properly 
fpeak- 
