2．只要细心，我都能算对．
| 0.5+$\frac{1}{2}$= | 10-3.7= | 35÷10%= | 0.125+0.875= | 48×5= |
| 2002÷22= | $\frac{8}{11}$÷$\frac{4}{11}$= | 0.23×400= | 1÷3= | 5÷$1\frac{2}{3}$= |
14．口算快车道．
0 158726 158734 158740 158744 158750 158752 158756 158762 158764 158770 158776 158780 158782 158786 158792 158794 158800 158804 158806 158810 158812 158816 158818 158820 158821 158822 158824 158825 158826 158828 158830 158834 158836 158840 158842 158846 158852 158854 158860 158864 158866 158870 158876 158882 158884 158890 158894 158896 158902 158906 158912 158920 199269
| 1-0.49= | $\frac{1}{4}$+$2\frac{3}{4}$= | 36×25%= | 3.2+0.8×3= | 253-199= |
| $\frac{1}{2}$÷$\frac{7}{4}$= | $\frac{9}{10}$×$\frac{5}{12}$= | 0.1×0.1= | 8.4÷0.7= | 2÷0.5= |