Question

口算 4 9 ÷ 2 3	1 3 × 3 7	3 4 ÷3	1- 5 8 × 8 5	64%+36%
1 4 × 1 5	0.72+0.28	1 5 - 1 6	3 4 × 2 5	2 3 × 5 6
7 9 ×18	3 10 ÷ 3 4	5 9 ÷ 5 6	21÷ 7 9	3 10 ÷ 2 5
6 11 × 22 7	5 9 ÷ 2 3	3 4 ×8	3÷ 1 5	10 21 ÷ 5 7
15 16 ÷ 5 8	1 4 ÷ 3 5	8 27 ÷ 2 9	8 9 ÷4	11 28 × 8 33
5 54 ×6	4× 3 4	5 7 × 21 5	6 7 × 7 9	5 8 × 4 15
2 3 × 4 5	7 25 × 15 14	85%-45%	2 3 × 3 5	1.2-0.9
0.5×0.2	1.2÷0.4	12× 3 4	1 4 ÷25%	1 5 × 2 3

Answer 1

考点：分数除法,分数的加法和减法,分数乘法,小数的加法和减法,小数乘法,小数除法

专题：计算题

分析：分数乘整数，用分数的分子和整数相乘的积做分子，分母不变；分数乘分数，用分子相乘的积做分子，分母相乘的积做分母，能约分的要约分；分数除以一个数（0除外），等于乘这个数的倒数．

解答： 解：

4 9 ÷ 2 3 = 2 3	1 3 × 3 7 = 1 7	3 4 ÷3= 1 4	1- 5 8 × 8 5 =0	64%+36%=1
1 4 × 1 5 = 1 20	0.72+0.28=1	1 5 - 1 6 = 1 30	3 4 × 2 5 = 3 10	2 3 × 5 6 = 5 9
7 9 ×18=14	3 10 ÷ 3 4 2 5	5 9 ÷ 5 6 = 2 3	21÷ 7 9 =27	3 10 ÷ 2 5 = 3 4
6 11 × 22 7 = 12 7	5 9 ÷ 2 3 = 5 6	3 4 ×8=6	3÷ 1 5 =15	10 21 ÷ 5 7 = 2 3
15 16 ÷ 5 8 = 3 2	1 4 ÷ 3 5 = 5 12	8 27 ÷ 2 9 = 4 3	8 9 ÷4= 2 9	11 28 × 8 33 = 2 21
5 54 ×6= 5 9	4× 3 4 =3	5 7 × 21 5 =3	6 7 × 7 9 = 2 3	5 8 × 4 15 = 1 6
2 3 × 4 5 = 8 15	7 25 × 15 14 = 3 10	85%-45%= 2 5	2 3 × 3 5 = 2 5	1.2-0.9=0.3
0.5×0.2=0.1	1.2÷0.4=3	12× 3 4 =9	1 4 ÷25%=1	1 5 × 2 3 = 2 15

点评：此题主要考查分数四则混合运算的方法的灵活应用．