| 直接写得数. 1÷ = | × = | + = | 2- = |
| 4.2×0.5= | 0.25×0.6= | 246+198= | - = |
= | = | = | 84.6+4= |
= | 10÷0.5= | = | 603×39≈ |
| 4980÷51≈ | 9.3÷0.03= | ÷2÷ = | 9- - . |
1÷ =9, | × = , | + = , | 2- =1 , |
| 4.2×0.5=2.1, | 0.25×0.6=0.15, | 246+198=444, | - = , |
=49, | =18, | =2, | 84.6+4=88.6, |
= , | 10÷0.5=20, | = , | 603×39≈24000, |
| 4980÷51≈100, | 9.3÷0.03=310, | ÷2÷ = , | 9- - =8. |
分析:246+198把198看成200-2简算;603×39≈600×40由此估算;4980÷51≈5000÷50由此估算;
÷2÷
先把除法变成乘法,再运用乘法交换律简算;9-
-
根据连续减去两个数等于减去这两个数的和简算;其它题目根据运算法则直接求解.点评:本题考查了基本的计算,注意分析式中数据,运用合适的简便方法计算.
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