15．口算
0 158543 158551 158557 158561 158567 158569 158573 158579 158581 158587 158593 158597 158599 158603 158609 158611 158617 158621 158623 158627 158629 158633 158635 158637 158638 158639 158641 158642 158643 158645 158647 158651 158653 158657 158659 158663 158669 158671 158677 158681 158683 158687 158693 158699 158701 158707 158711 158713 158719 158723 158729 158737 199269
| 2.5×40= | 0.77+0.33= | 0.7×0.07= | 4.7+3= | 0.1×0.1÷0.1= |
| 8.93-0.3= | 0.24×5= | 32÷53×0= | 1-0.1×0.1= | 0.1-0.1×0.1= |