1 直接写出得数。(每题1分,共20分)
$21.7÷0.7= $ $9.6÷6= $ $44÷11= $ $0.4×5= $
$2.43+3.17= $ $0.33÷0.11= $ $2.2-1.3= $ $0.8-0.05= $
$0.35-0.25= $ $6.6+1.7= $ $9.6÷1.2= $ $175.8-86.7= $
$4.2-3.1= $ $8.95-2.33= $ $45×0.6= $ $10.6-2.7= $
$3.27-1.58= $ $56×0.7= $ $0÷21.35= $ $2.8+1.2= $

31 1.6 4 2
5.6 3 0.9 0.75
0.1 8.3 8 89.1
1.1 6.62 27 7.9
1.69 39.2 0 4

2 计算下列各题,能简算的要简算。(每题3分,共18分)
$6.33×101$ $87×1.63+16.3×1.3$ $7.8-1.25+2.2-8.75$
$8.6×1.2×2.5$ $3.4×12.5+6.6×12.5$ $0.78×98$

639.33 163 0
25.8 125 76.44

3 解方程。(每题4分,共12分)
$2.7+4x= 12.7$ $3.98+x= 6.25$ $3.6x-0.8x= 26.6$

解:$x=2.5$ 解:$x=2.27$ 解:$x=9.5$