直接写得数. + = | - = | 0.2- = |
+ = | - = | +2÷9= |
2- - = | 1.55- = | 1- - + = |
0.5- - = |
解: + =1 | - =![]() | 0.2- =0.1 |
+ =![]() | - =![]() | +2÷9=1 |
2- - =1 | 1.55- =1.05 | 1- - + =![]() |
0.5- - =0.05 |
,0.1,
,
,1,1,1.05,
,0.05.分析:2-
-
根据连续减去两个数等于减去这两个数的和来简算;1-
-
+
,运用加法结合律简算;0.5-
-
都化成小数,再根据连续减去两个数等于减去这两个数的和来简算;其它题目按照运算法则直接运算.点评:本题考查了基本的计算,在有小数和分数的算式先观察都化成哪种形式的数更易计算.
+
=
=
+
=
-
+2÷9=