640709000647090000 3000平方米3公顷
8000000008亿 450×245×20
12×4= 25×40= 36×2= 180×5=
60×4= 24×50= 5×16×2= 48+2=
①308×52=
②680×50=
③160×51=
④13×25=
⑤73×426=
⑥151×29=