SHORT CALCULATION 7g] 



unit figure of each of the preceding totals affixed one after the other, 

 reading upward. For example : We will suppose the following amounts 

 to be the sums total of certain columns of figures in an example, and that 

 they come in order, one under the other, as here placed, 98, 120, 65, 24, 

 the sum total is 24508. In putting down the sum total of each column 

 in this manner, the amount to be carried to the next column is the figures 

 to the left of the unit number in the first above, it is 9 ; in the second, 

 12, and so on. The object in putting down the totals in this mannc 

 that if in going over the addition a second time, the second addition does 

 not agree with the first, we are not obliged to commence again from the 

 beginning, but may commence with the figures to the left of the unit num- 

 ber in the column preceding and " try it again." 



MULTIPLICATION. 



86O. To multiply by any number between 10 and 20, multiply by the 

 unit figure ; set the product thus found one place to the right, under the 

 multiplicand, and add. The sum will be the answer. For example : In 

 multiplying 324 by 17, we simply multiply by 7 in the manner above in- 

 dicated, thus : 



324 

 2268 



5o08 



In order to give an idea of rapid calculation in multiplication a few ex- 

 amples will here be given, and from these others may be created without 

 limit by any one : 



35 yards cloth @ $2.50 Add one cipher and divide by 4. Answer, 87fc or $87.50. 



432 

 210 " $2.25. Multiply 2J$ by setting down the amounts thus 64 



$486 



48 @ $2.12$. Multiply by 2J$ in the samo manner as by 2J$. 



55 @ $1.95. Move decimal point in price two places to the right, divil 



195 by 2 and add ^ thus : '.'7.50 



ft.75 



<9 $).80. Multiply by 2 and deduct ^ thus : 



$201.60 



