①27+38+12
②83-46-24
③43+(56-24)
④85-(43-28)
37+30= 6÷3= 76+18= 6×6-5=
4×2+3= 4÷2+5= 41-21= 5×4-4=
85-40= 26+9= 2+35= 25÷5=
或
口诀:
38+29+30 87-30-42 68-(46-24)
①39+36+8=
②98-36-47=
③100-9-28=
④76-57+32=
⑤58+24-49=
⑥56-(9+38)=
好=