1. 直接写出得数。
$5 - 2.7 =$ $2.6×5 =$ $16 - 0.164 =$
$8.02×3 =$ $90.3÷10 =$ $19.9×0.1 =$
$2.4×5 =$ $2.4×0.5 =$ $0.24×0.05 =$
$230÷1000 =$ $\frac{11}{27} + \frac{8}{27} =$ $\frac{9}{10} - \frac{2}{10} =$
$\frac{8}{11} - \frac{5}{11} =$ $\frac{3}{8} + \frac{5}{8} =$ $1 - \frac{2}{5} =$
$0.7×1.2 =$ $5.3×0.4 =$ $0.96×0.5 =$
$4.01×7 =$ $2.2×0.4 =$ $3.7×0.2 =$
$0.04×90 =$ $45×0.02 =$ $0.9×10×0.1 =$

5 - 2.7 = 2.3 2.6×5 = 13 16 - 0.164 = 15.836
8.02×3 = 24.06 90.3÷10 = 9.03 19.9×0.1 = 1.99
2.4×5 = 12 2.4×0.5 = 1.2 0.24×0.05 = 0.012
230÷1000 = 0.23 $\frac{11}{27} + \frac{8}{27} = \frac{19}{27}$ $\frac{9}{10} - \frac{2}{10} = \frac{7}{10}$
$\frac{8}{11} - \frac{5}{11} = \frac{3}{11}$ $\frac{3}{8} + \frac{5}{8} = 1$ $1 - \frac{2}{5} = \frac{3}{5}$
0.7×1.2 = 0.84 5.3×0.4 = 2.12 0.96×0.5 = 0.48
4.01×7 = 28.07 2.2×0.4 = 0.88 3.7×0.2 = 0.74
0.04×90 = 3.6 45×0.02 = 0.9 0.9×10×0.1 = 0.9

2. 计算下列各题，能简算的要简算。
$70.8 - 1.25 - 1.75$ $(8 + 0.8)×1.25$
$4.62×15.8 + 15.8×5.38$ $24.21 + 13.98 - 13.21$
$29.7 - 9.65 - 5.35$ $11.8×0.6 - 1.8×0.6$
$8.23×10.1$ $3.09 - 1.19×0.35$

$70.8 - 1.25 - 1.75$
$=70.8 - (1.25 + 1.75)$
$=70.8 - 3$
$=67.8$
$(8 + 0.8)×1.25$
$=8×1.25 + 0.8×1.25$
$=10 + 1$
$=11$
$4.62×15.8 + 15.8×5.38$
$=15.8×(4.62 + 5.38)$
$=15.8×10$
$=158$
$24.21 + 13.98 - 13.21$
$=24.21 - 13.21 + 13.98$
$=11 + 13.98$
$=24.98$
$29.7 - 9.65 - 5.35$
$=29.7 - (9.65 + 5.35)$
$=29.7 - 15$
$=14.7$
$11.8×0.6 - 1.8×0.6$
$=0.6×(11.8 - 1.8)$
$=0.6×10$
$=6$
$8.23×10.1$
$=8.23×(10 + 0.1)$
$=8.23×10 + 8.23×0.1$
$=82.3 + 0.823$
$=83.123$
$3.09 - 1.19×0.35$
$=3.09 - 0.4165$
$=2.6735$