1 直接写出得数。(每题1分,共20分)
$1.5÷5= $ $138.7-69.2= $ $0.875-0.625= $ $6.15+3.22= $
$1.25+3.75= $ $167+258= $ $8.2+4.5= $ $2.4-1.5= $
$3.14÷3.14= $ $1.8×20= $ $3.3-2.2= $ $4.68+9.22= $
$685-357= $ $84+47.9= $ $0.575-0.375= $ $1.8÷0.3= $
$2.18+8.49= $ $47.5-32.1= $ $684+549= $ $0.16÷0.04= $

0.3 69.5 0.25 9.37
5 425 12.7 0.9
1 36 1.1 13.9
328 131.9 0.2 6
10.67 15.4 1233 4

2 计算下列各题,能简算的要简算。(每题3分,共18分)
$4.62×101+3.38$ $12.5×3.9×0.8$ $6.7×101$
$25×44$ $478-149-51$ $2.2+3.4+7.8+2.6$

470 39 676.7
1100 278 16

3 解方程。(每题4分,共12分)
$1.2×6+8x= 12$ $7.8x-6.5x= 3.9$ $x÷0.6= 0.42$

解:$x=0.6$ 解:$x=3$ 解:$x=0.252$