Haggerty : Study in Arithmetic 



431 



11 



10 



9- 



8 



ATTEMPTS 

 7 



RIGHTS 



11 



_ I I 



. < l_ I- 



I I 



15 



12 



13 



r -I 

 I I 

 rf I 

 I.. 



J _i 



56 



113 



59 '56 72 



167 



60' 



- -h 



103 



-I - 



1 - 

 L 



66|122 %'80 



160 



12: 



54 



124 



67 



COURTIS 



IKDIVIDUAL 

 €ITY 

 BOSTON 

 DETROIT 



COURTIS 



h mDrVTDUAL 

 rCITY 



-DETROIT 

 ■BOSTON 



500 1000 

 FIG. 10 MEDIANS GRADE 7 series r 



SUBTRACTION 



1500 



