Question

口算显身手！ 3 8 × 6 5 =	1 3 × 4 5 =	7 15 ×3=	3 5 × 1 3 =	7 9 ×0=
1 3 × 1 8 =	2 7 × 1 3 =	2 3 × 2 7 =	7 15 × 2 14 =

Answer 1

分析：①③④⑨约分计算；②⑥⑦⑧分子相乘的积作分子，分母相乘的积做分母；⑤0乘任何数都得0．

解答：

解： 3 8 × 6 5 = 9 20	1 3 × 4 5 = 4 15	7 15 ×3= 7 5	3 5 × 1 3 = 1 5	7 9 ×0=0
1 3 × 1 8 = 1 24	2 7 × 1 3 = 2 21	2 3 × 2 7 = 4 21	7 15 × 2 14 = 1 15

点评：掌握分数乘法的计算方法，是解答此题的关键．