947+(372-447)= 284+198= 998+3+99+998+3+9= 958-596= 85+41+15+59= 34+304+3004=

问题描述:

947+(372-447)=
284+198=
998+3+99+998+3+9=
958-596=
85+41+15+59=
34+304+3004=

(1)947+(372-447)
=947-447+372
=500+372
=872;
(2)284+198
=284+200-2
=484-2
=482;
(3)998+3+99+998+3+9
=(998+2)+(1+99)+(998+2)+(1+9)
=1000+100+1000+10
=2110;
(4)958-596
=958-600+4
=358+4
=362;
(5)85+41+15+59
=(85+15)+(59+41)
=100+100
=200;
(6)34+304+3004
=30+300+3000+4+4+4
=3330+12
=3342.