405+364=?,290+422=?,460+742=?
700-42=?,939-683=?,905-129=?
55+?=813,201+?=705,346+?=940
74*7=?,61*9=?,523*3=?
408/8=?,620/5=?,714/6=?
---
?-288=890-489,165+169+442+122=?
780-243=?+317,512+335+227-988=?
265+?+368=926,402+414-260-381=?
232+?-506=485,999-215-172-462=?
到处捡垃圾