200 + 19 = (a)  

300 - 56 = (a)  

450 - 281 = (a)  

164 + 102 = (a)  

482 - 391= (a)  

1000 - 789 = (a)  

889 - 691 = (a)  

175 + 244 = (a)  

572 + 428 = (a)