13.
| 直接写出得数. $\frac{1}{18}$+$\frac{5}{9}$= | 6$\frac{6}{7}$÷3= | $\frac{3}{4}$×1.2= | $\frac{5}{8}$÷$\frac{2}{3}$= |
| 17×25×4= | 630÷7÷9= | 12-12×$\frac{3}{4}$= | 6.4×(1$\frac{1}{4}$-1.25)= |
8.把一根5米长的钢管,平均分成4段,每段钢管长( )米.
| A. | $\frac{1}{4}$ | B. | $\frac{5}{4}$ | C. | $\frac{1}{5}$ |
7.制作一个棱长为20cm的正方体灯笼框架,至少需要( )cm长的木条.
| A. | 60 | B. | 160 | C. | 240 |
6.若一组数1,2,3,4,a的平均数是3,则a的值是( )
0 158640 158648 158654 158658 158664 158666 158670 158676 158678 158684 158690 158694 158696 158700 158706 158708 158714 158718 158720 158724 158726 158730 158732 158734 158735 158736 158738 158739 158740 158742 158744 158748 158750 158754 158756 158760 158766 158768 158774 158778 158780 158784 158790 158796 158798 158804 158808 158810 158816 158820 158826 158834 199269
| A. | 5 | B. | 4 | C. | 3 |