12．估算：
0 158469 158477 158483 158487 158493 158495 158499 158505 158507 158513 158519 158523 158525 158529 158535 158537 158543 158547 158549 158553 158555 158559 158561 158563 158564 158565 158567 158568 158569 158571 158573 158577 158579 158583 158585 158589 158595 158597 158603 158607 158609 158613 158619 158625 158627 158633 158637 158639 158645 158649 158655 158663 199269
| 71÷8= | 125÷2= | 297÷4= |
| 360÷5= | 138÷7= | 440÷9= |
