DIVISION 11 



(2) To multiply any whole number by 33 J, annex two 

 ciphers to the number and divide by 3. 



Since 33^ = % of 100, to annex two ciphers to any num- 

 ber and divide by 3 is the same as to multiply by 33^. 



EXAMPLE. 132 x 33J = 13200 -- 3 = 4400. 



EXERCISE 



1. Show that to multiply 1728 by 12^ is the same as to 

 multiply by 100 and divide by 8. 



2. Show that to multiply 364 by 25 is the same as to 

 multiply by 100 and divide by 4. 



3. Show that to multiply 1488 by 8J is the same as to 

 multiply by 100 and divide by 12. 



4. Show that to multiply 1648 by 6J is the same as to 

 multiply by 100 and divide by 16. 



5. Multiply 936 by 8' ; by 12| ; by 16 ; by 25 ; by 33 J. 



DIVISION 



14. The following short methods of division are useful. 



(1) To divide any whole number by 10, point off one 

 decimal place ; if a decimal or mixed number is to be 

 divided by 10, move the decimal point in the number one 

 place to the left. 



EXAMPLE. 867 +- 10 = 86.7. 



36.5 - 10 = 3.65. 



ORAL EXERCISE 



Name rapidly the quotients of the following numbers 

 when divided by 10; by 100. 



1. 87. 3. 273. 5. 638. 7. 1.6. 



2. 345. 4. 379. 6. 724. 8. 2780. 



