1. 口算。（建议用时3分钟）
4.8 + 20% =
700×0.6% =
90×50%×20% =
60÷30% =
80×12.5% =
78×(1+30%) =
1−30% =
2.5×40% =
120×(1−70%) =
75%÷5% =
6÷50% =
50%×8 +25% =
10×6.6% =
2.4÷20% =
60×(1−20%) =
87.5% × $\frac{16}{7}$ =
$\frac{4}{5}$ ÷60% =
1−80% × $\frac{1}{8}$ =

4.8 + 20% = 5
700×0.6% = 4.2
90×50%×20% = 9
60÷30% = 200
80×12.5% = 10
78×(1+30%) = 101.4
1−30% = 0.7
2.5×40% = 1
120×(1−70%) = 36
75%÷5% = 15
6÷50% = 12
50%×8 +25% = 4.25
10×6.6% = 0.66
2.4÷20% = 12
60×(1−20%) = 48
87.5% × $\frac{16}{7}$ = 2
$\frac{4}{5}$ ÷60% = $\frac{4}{3}$
1−80% × $\frac{1}{8}$ = 0.9

2. 填表。（建议用时2分钟）
| 百分数 | 75% | | | | 0.5% | |
| ---- | ---- | ---- | ---- | ---- | ---- | ---- |
| 小 数 | | 1.2 | | 0.45 | | |
| 分 数 | | | $\frac{5}{8}$ | | | $\frac{2}{5}$ |

0.75 $\frac{3}{4}$
120% $\frac{6}{5}$
62.5% 0.625
45% $\frac{9}{20}$
0.005 $\frac{1}{200}$
40% 0.4

3. 计算下面各题,能用简便算法的就用简便算法。(建议用时2分钟)
$84÷(66\% - 46\%)$
$(\dfrac{2}{51} + \dfrac{5}{34})×6×17$
$160×(1 - \dfrac{1}{4} + 20\%)$

$84÷(66\% - 46\%)$ = 420
$(\dfrac{2}{51} + \dfrac{5}{34})×6×17$ = 19
$160×(1 - \dfrac{1}{4} + 20\%)$ = 152

4. 解决问题。(建议用时3分钟)
驴肉火烧是河北省河间市的传统小吃。甲、乙、丙三家店都在售卖同一款驴肉火烧精品礼盒，每盒标价120元，但促销活动不同：甲店打八折出售，乙店降价15%出售，丙店按“每满120元减20元”出售。买一盒这款礼盒，在哪家店购买最划算？

甲店:$120×80\%=96$(元)
乙店:$120×(1−15\%)=102$(元)
丙店:$120−20=100$(元)
$96＜100＜102$
在甲店购买最划算