Question

直接寫出得數(shù)．

31+1.8=	3 7 ×2.8=	6.24÷6=	5 11 ÷ 5 12 =
5.6× 5 8 =	3.6÷ 12 25 =	12-7 4 9 =	2 3 × 1 4 =
6 7 -0.5=	2 1 3 +1 5 6 =	0÷1 1 5 =	7 9 ÷ 1 9 =
3-3÷4=	1 7 ×1 1 6 =	5 2 5 -1.9-3.1=	（ 2 3 - 1 6 ）×6=

Answer 1

考點：小數(shù)的加法和減法,運算定律與簡便運算,分?jǐn)?shù)乘法,分?jǐn)?shù)除法,整數(shù)、分?jǐn)?shù)、小數(shù)、百分?jǐn)?shù)四則混合運算

專題：計算題

分析：根據(jù)小數(shù)和分?jǐn)?shù)加減乘除法的計算方法進行計算．
5

2

5

-1.9-3.1根據(jù)減法的性質(zhì)進行簡算；
（

2

3

-

1

6

）×6根據(jù)乘法分配律進行簡算．

解答： 解：

31+1.8=32.8	3 7 ×2.8=1.2	6.24÷6=1.04	5 11 ÷ 5 12 = 12 11
5.6× 5 8 =3.5	3.6÷ 12 25 =7.5	12-7 4 9 =4 5 9	2 3 × 1 4 = 1 6
6 7 -0.5= 5 14	2 1 3 +1 5 6 =4 1 6	0÷1 1 5 =0	7 9 ÷ 1 9 =7
3-3÷4=2.25	1 7 ×1 1 6 = 1 6	5 2 5 -1.9-3.1= 2 5	（ 2 3 - 1 6 ）×6=3

點評：口算時，注意運算符號和數(shù)據(jù)，然后再進一步計算．