①589+257+143
②536﹣183+264
③735﹣229﹣171
④589﹣297
⑤398+254
⑥858﹣(458+235)
25+46=
257+390=
77+23=
182+318=
200+36+164=
77+23+89=
46+54+38=
135+65+800=