乘法分配律专项练习

公式: (a+b)×c = a×c + b×c 逆运算: a×c + b×c = (a+b)×c 注意: 99×a + a = 99×a + 1×a

一、提取公因数 (注意找对朋友)

21 + 21 × 99 =

2100

41 × 60 + 40 × 41 =

4100

57 × 6 + 4 × 57 =

570

6 × 93 + 4 × 93 =

930

26 × 13 + 87 × 26 =

2600

64 × 81 + 36 × 81 =

8100

26 × 66 + 26 × 34 =

2600

18 × 61 + 18 × 39 =

1800

5 × 14 + 5 × 14 =

140

二、拆成 (100+N) 再计算

11 × 201 =

2211

27 × 201 =

5427

55 × 201 =

11055

72 × 101 =

7272

52 × 101 =

5252

101 × 40 =

4040

201 × 65 =

13065

21 × 101 =

2121

78 × 101 =

7878

三、拆成 (100-N) 再计算

80 × 99 =

7920

99 × 14 =

1386

55 × 99 =

5445

32 × 99 =

3168

67 × 99 =

6633

16 × 98 =

1568