Haggerty : Study in Arithmetic 



427 



the left ordinate indicate the number of problems. The figures 

 at the bottom of the form indicate the number of children reported 

 from each city, and the horizontal space on the chart allotted to 

 each city is proportional to this number. 



The dotted lines represent attempts, and the solid lines show 



s ■ 



•-r_r-"-~-~L- 



1 - 



i-:^?A-:->^:-:->3":-:? 



135 ' 113 



1 I 



J. J_ 



-j.-_r_ 



168 'b5, 



XBOSTON 

 DETROIT 

 COURTIS 



BOSTON COURTIS 



^DivrouAL 



DETROIT^CITY 



30 O 



riG.b MEDIANS 



1000 



GRADE 6 SERIES B 



1500 



StJBTRACTlON 



rights. Both the city and individual averages are represented by 

 horizontal lines across the full width of the chart. Similarly there 

 are sho^Ti the Courtis general standard score for February, 1914, 

 3,618 children ; the Detroit score for February, 1914, 1,315 children ; 

 and the Boston score for February, 1914, 20,441 children. All of 

 these are indicated on the right of the chart^. 



The reader may study the tables in either of two ways. He 



■ Courtis, S. A. Bulletin Number Three (Detroit, 1914) , 



