475×6= 96×7= ★721÷7 = 验算:
308×9= 76÷4= ★590÷8 = 验算:
①520+130=
②180+650=
③880-320=
④730-280=
⑤480+320=
⑥700-260=
①424+525=
②436+759=
③☆263+738=
④879-229=
⑤805-362=
⑥☆900-198=