56+29= 74+20= 43+25= 65-32=
38+42= 88-49= 57-29= 48+36=
770-570= 400-270= 690-380= 470+360=
①234×2=
②*165+283=
③*310-183=
④1000-694=
⑤378×3=
⑥105×8=