1.直接写出得数。
9×3=
1.5×2=
6×3.5=
3.2×3=
2.9×2=
0.8×0.8=
0.04×12=
1.2×0.6=
1.25×8=

9×3=27
1.5×2=3
6×3.5=21
3.2×3=9.6
2.9×2=5.8
0.8×0.8=0.64
0.04×12=0.48
1.2×0.6=0.72
1.25×8=10

2.脱式计算。
40×40×2
1.8×4×5
0.3×0.2×3
0.1×0.1×9
4.5×4×3
3.2×5×9
$\frac{2}{3}+\frac{5}{6}-\frac{2}{3}$
$\frac{1}{6}+\frac{2}{3}+\frac{2}{3}$
$\frac{5}{8}+\frac{1}{8}+\frac{3}{8}$
$\frac{5}{6}-\frac{1}{6}+\frac{2}{5}$
$\frac{5}{12}+\frac{7}{12}-\frac{7}{11}$
$\frac{17}{30}-\frac{1}{15}-\frac{4}{15}$

40×40×2
=1600×2
=3200
1.8×4×5
=1.8×(4×5)
=1.8×20
=36
0.3×0.2×3
=0.06×3
=0.18
0.1×0.1×9
=0.01×9
=0.09
4.5×4×3
=18×3
=54
3.2×5×9
=16×9
=144
$\frac{2}{3}+\frac{5}{6}-\frac{2}{3}$
=$\frac{2}{3}-\frac{2}{3}+\frac{5}{6}$
=0+$\frac{5}{6}$
=$\frac{5}{6}$
$\frac{1}{6}+\frac{2}{3}+\frac{2}{3}$
=$\frac{1}{6}+\frac{4}{6}+\frac{4}{6}$
=$\frac{9}{6}$
=$\frac{3}{2}$
$\frac{5}{8}+\frac{1}{8}+\frac{3}{8}$
=$\frac{6}{8}+\frac{3}{8}$
=$\frac{9}{8}$
$\frac{5}{6}-\frac{1}{6}+\frac{2}{5}$
=$\frac{4}{6}+\frac{2}{5}$
=$\frac{2}{3}+\frac{2}{5}$
=$\frac{10}{15}+\frac{6}{15}$
=$\frac{16}{15}$
$\frac{5}{12}+\frac{7}{12}-\frac{7}{11}$
=$\frac{12}{12}-\frac{7}{11}$
=1-$\frac{7}{11}$
=$\frac{4}{11}$
$\frac{17}{30}-\frac{1}{15}-\frac{4}{15}$
=$\frac{17}{30}-(\frac{1}{15}+\frac{4}{15})$
=$\frac{17}{30}-\frac{5}{15}$
=$\frac{17}{30}-\frac{10}{30}$
=$\frac{7}{30}$