| 276+198= | 10-1.6= | 0.25×0.125= | 1÷50%= |
+ = | ÷ = | + × = | 2× ÷2× = |
| 解:276+198=474, | 10-1.6=8.4, | 0.25×0.125= , | 1÷50%=2, |
+ = , | ÷ = , | + × = , | 2× ÷2× = . |
分析:把276+198改写成276+200-2,从而简算;
+
×
,按照先算乘法,再算加法的顺序计算;把2×
÷2×
改写成2÷2×
×
,从而简算;其它算式按照整数、小数、分数四则运算的方法计算得解.
点评:此题考查看算式直接写得数,要根据数据和运算符号的特点,灵活选用简便的方法进行口算.
÷
=
,
,
,
.