SIMPLE SUBTE ACTION. 



»9 



2. Begin at the right hand, and iake each figure in tlie 

 Jovver line from the iigure above it, an4 $et down the re- 

 ^nainder. 



3. If the lower figure is greater than that ahove it, add 

 ten to the upper figure ; from which figure, so increased, 

 take the lower, and set down the remainder, carrying one 

 to the next lower figure -, with which proceed as before, 

 ;inJ so on till the whole is finished* 



Mahod of Proop. 



Add the remainder to the less numher, ar4 if tfi^ suni 

 is equal to the greater, the work is right. 



EXAUPLES. 



From 3287625 

 Take 2343756 



From^ 5327467 

 Take IC08438 



From 1231567 

 Take 345^7^ 



Reraaind. 943869 Remain. 4319029 

 Proof 3287625 Proof 5327467 



Remain. 888889 



Froof ^ 1234567 

 4. From 



2. When any figure of the greater number is less than its cor- 

 respondent figure in the less, the ten, which is added by the rule, 

 is the value of an unit in the next higher place, by the nature of 

 notation ; and the one that is added to the next place of the less 

 number is to diminish the correspondent place of the greater ac- 

 cordingly ; which is only takiing from one place and adding as 

 much to another, whereby the total is never changed, And by 

 this nieans the greater number is resolved into such parts, as are 

 each greater than, or equal to, the similar parts of the less : and 

 tlie difference of the corresponding figures, taken together, will 

 evidently make up the difference of the whole. Q^E. D. 



The truth of the method of-proof is evident : for the diffei:ence 

 of two numbers, added to the less, is manifeilly c^ual to the 

 (greater. 



