一、脱式计算
580-(1225-291)=
(30-18226)32=
642-(36+132)4=
178+3225=
79+6468=
956+3757=
893+93549=
74+59608=
563+3748=
993+18360=
92+27038=
256+5769-98=
123+1326=
93+2336=
71+89716=
236+1276-76=
525+2639=
999+5967=
302+3867=
36+2738+987=
82+3627=
45+24012=
124+978+292=
100-35-25=
(140-70)54=
63+84242=
4907+245=
2696-110=
(46-20)30-90=
25274=
157+857=
(40-4)25=
240080-142=
108-(83+36060)=
(960-400)70=
290-(343+99)=
142-549+14=
1676-766=
9953+53=
450-2(16+9)=
125(84)5=
4125-25=
420(205-198)4=
460(29-183)=