12 FUNDAMENTAL PROCESSES 



ORAL EXERCISE 



Name rapidly the quotients of the following numbers 

 when divided by 10. 



1. 87. 5. 273. 9. 638. 13. 1.6. 



2. 345. 6. 379. 10. 724. 14. 2780. 



3. 75. 7. 274. 11. 3.7. 15. 8.9. 



4. 169. 8. 577. 12. 24.5. 16. 47.5. 



(2) To divide any whole number by 33J, point off two 

 decimal places and multiply by 3 ; if the number is a deci- 

 mal or mixed number, move the decimal point two places 

 to the left and multiply by 3. 



Since 33^ = ^ of 100, to move the decimal point two 

 places to the left and multiply by 3 is the same as to divide 

 by 33|. 



EXAMPLE. 648 -- 33 = 6.48 x 3 = 19.44. 



(3) To divide any number by 16, move the decimal 

 point in the number two places to the left and multiply by 6. 



Since 16 = of 100, to move the decimal point in the 

 number two places to the left and multiply by 6 is the same 

 as to divide by 16f . 



EXAMPLE. 546 ~- 16 J = 5.46 x 6 = 32.76. 



EXERCISE 



1. Show that to divide 484 by 25 is the same as pointing 

 off two decimal places in the dividend and multiplying by 4. 



2. Explain a short method for dividing 2567 by 50; by 



3. Divide 8976 by 33J ; by 12| ; by 16f ; by 25 ; by 50. 



