Question

直接寫得數(shù) 2 5 × 5 7 =	25× 1 10 =
1 5 - 1 6 =	15× 4 5 =
5 6 - 2 3 =	4 9 × 3 8 =
1 2 + 1 3 =	19 53 × 2 5 ×0=
2- 6 13 =	100× 3 25 =

Answer 1

分析：異分母分數(shù)相加減，先通分，變成同分母的分數(shù)再相加減；
分數(shù)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 × 5 7 = 2 7	25× 1 10 = 5 2
1 5 - 1 6 = 1 30	15× 4 5 =12
5 6 - 2 3 = 1 6	4 9 × 3 8 = 1 6
1 2 + 1 3 = 5 6	19 53 × 2 5 ×0=0
2- 6 13 =1 7 13	100× 3 25 =12．

點評：本題考查了分數(shù)乘法和加減法的計算，計算時要細心，注意把結果化成最簡分數(shù)．