SUBTEACTION 



7. The first five minutes of each recitation period for 

 several days, or perhaps weeks, should be spent in drill on 

 these exercises and similar ones prepared by the teacher. 

 The time spent in drill is regained by the pupil in the sav- 

 ing of his time, due to the accuracy and rapidity with which 

 he prepares his lesson. 



SUBTRACTION 



8. The process of finding the difference between two 

 numbers is made much easier and more rapid if the pupil 

 is able to see at a glance what number added to the smaller 

 of two numbers, of one or two figures each, will produce the 

 larger. Thus, if 13 is to be subtracted from 27, the pupil 

 should think of 14, the number which added to 13 pro- 

 duces 27. 



