1. 直接写出得数。
$0.7×0.8=$ $65÷13=$ $3×2.7=$
$0×0.18=$ $0.4×60=$ $0.36×0.6=$
$50×0.09=$ $3.2×0.04=$ $25×0.2÷25×0.2=$
$8.9×2=$ $10×0.25=$ $2.5×3.5×0.4=$
$19.3+0.9=$ $7800÷600=$ $100÷1000=$

0.7×0.8=0.56
65÷13=5
3×2.7=8.1
0×0.18=0
0.4×60=24
0.36×0.6=0.216
50×0.09=4.5
3.2×0.04=0.128
25×0.2÷25×0.2=0.04
8.9×2=17.8
10×0.25=2.5
2.5×3.5×0.4=3.5
19.3+0.9=20.2
7800÷600=13
100÷1000=0.1

2. 计算下列各题，能简算的要简算。
$25.63+3.7×2.8$ $9.2+9.728+3.2×1.5$
$8.6×10.1$ $8.4-0.2-0.5$
$9.9+9.9×99$ $5.78×2.57+2.57×3.22+2.57$
$856+97$ $8.32×101-8.32$
$25.38-(7.4-0.62)$ $5.8+8.63+4.2+0.37$
$3.27+3.9+0.73+16.1$ $37.5+4.9-7.5$

25.63+3.7×2.8
=25.63+10.36
=35.99
9.2+9.728+3.2×1.5
=9.2+9.728+4.8
=(9.2+4.8)+9.728
=14+9.728
=23.728
8.6×10.1
=8.6×(10+0.1)
=8.6×10+8.6×0.1
=86+0.86
=86.86
8.4-0.2-0.5
=8.4-(0.2+0.5)
=8.4-0.7
=7.7
9.9+9.9×99
=9.9×(1+99)
=9.9×100
=990
5.78×2.57+2.57×3.22+2.57
=2.57×(5.78+3.22+1)
=2.57×10
=25.7
856+97
=856+100-3
=956-3
=953
8.32×101-8.32
=8.32×(101-1)
=8.32×100
=832
25.38-(7.4-0.62)
=25.38-7.4+0.62
=25.38+0.62-7.4
=26-7.4
=18.6
5.8+8.63+4.2+0.37
=(5.8+4.2)+(8.63+0.37)
=10+9
=19
3.27+3.9+0.73+16.1
=(3.27+0.73)+(3.9+16.1)
=4+20
=24
37.5+4.9-7.5
=37.5-7.5+4.9
=30+4.9
=34.9