11．口算
0 162467 162475 162481 162485 162491 162493 162497 162503 162505 162511 162517 162521 162523 162527 162533 162535 162541 162545 162547 162551 162553 162557 162559 162561 162562 162563 162565 162566 162567 162569 162571 162575 162577 162581 162583 162587 162593 162595 162601 162605 162607 162611 162617 162623 162625 162631 162635 162637 162643 162647 162653 162661 199269
| 750-430= | 880-520= | 960-500= | 540-80= |
| 530-360= | 420+80= | 730+90= | 270+60= |
| 680+40= | 420+380= | 15万+25万= | 73万-26万= |
| 24万+63万= | 90万-68万= | 230万-70万= |