1. 直接写得数。
6.2-1.9 =
0.82+3.18 =
16.16÷4 =
0.54÷0.6 =
0.25+0.75 =
8×0.4 =
2.4×0.2 =
7.5÷0.5 =

答题卡：
1.
6.2 - 1.9 = 4.3
0.82 + 3.18 = 4
16.16 ÷ 4 = 4.04
0.54 ÷ 0.6 = 0.9
0.25 + 0.75 = 1
8 × 0.4 = 3.2
2.4 × 0.2 = 0.48
7.5 ÷ 0.5 = 15

2. 计算下列各题,能简算的要简算。
30.8÷[14-(9.85+1.07)]
37÷12.5÷0.8
0.97×9+0.97
5×[(3.1+4.1)÷1.8]
7.5×101
32×1.25×2.5
8.4×0.6+8.4÷0.6

1.
$30.8÷[14 - (9.85 + 1.07)]$
$=30.8÷[14 - 10.92]$
$=30.8÷3.08$
= 10
2.
$37÷12.5÷0.8$
$=37÷(12.5×0.8)$
$=37÷10$
= 3.7
3.
$0.97×9 + 0.97$
$=0.97×(9 + 1)$
$=0.97×10$
= 9.7
4.
$5×[(3.1 + 4.1)÷1.8]$
$=5×[7.2÷1.8]$
$=5×4$
= 20
5.
$7.5×101$
$=7.5×(100 + 1)$
$=7.5×100+7.5×1$
$=750 + 7.5$
= 757.5
6.
$32×1.25×2.5$
$=4×8×1.25×2.5$
$=(4×2.5)×(8×1.25)$
$=10×10$
= 100
7.
$8.4×0.6+8.4÷0.6$
$=5.04 + 14$
= 19.04

3. 给下列算式添上括号,使计算正确。
4.6+9-4.4×9 = 4.6+4.6×9 = 46
18.8÷8.4+11.6÷4 = 18.8÷20÷4 = 18.8÷5 = 3.76

1. 4.6 + (9 - 4.4) × 9 = 46
2. 18.8 ÷ [(8.4 + 11.6) ÷ 4] = 3.76