Question

直接寫出結果． 2 5 ×4=	10 21 × 3 5 =	24× 5 8 =	5 7 + 1 5 =	5 16 × 8 15 =	12 19 × 7 24 =
1 2 - 1 6 =	27 34 × 17 18 =	5 44 ×33=	6× 4 7 =	2 3 × 9 10 =	3 13 ×39=
7 18 ×3.6=	1.6× 4 5 =	2.4× 7 8 =	4 7 ×0.75=

Answer 1

考點：分數乘法

專題：運算順序及法則

分析：分數乘法：分子相乘的積做分子，分母相乘的積做分母，能約分的先約分．

解答：

解： 2 5 ×4=1 3 5	10 21 × 3 5 = 2 7	24× 5 8 =15	5 7 + 1 5 = 32 35	5 16 × 8 15 = 1 6	12 19 × 7 24 = 7 38
1 2 - 1 6 = 1 3	27 34 × 17 18 = 3 4	5 44 ×33=3 3 4	6× 4 7 =3 3 7	2 3 × 9 10 = 3 5	3 13 ×39=9
7 18 ×3.6=1.4	1.6× 4 5 =1.28	2.4× 7 8 =2.1	4 7 ×0.75= 3 7

點評：本題考查了簡單的分數計算，計算時要細心，注意把結果化成最簡分數．