①9-0.64-0.36
②1.8×
+2.2×25%③6.25-40÷16×2.5.解:①9-0.64-0.36,
=9-(0.64+0.36),
=9-1,
=8;
②1.8×
+2.2×25%,=1.8×
+2.2×
,=(1.8+2.2)×
,=4×
,=1;
③6.25-40÷16×2.5,
=6.25-2.5×2.5,
=6.25-6.25,
=0.
分析:①根据连续减去两个数等于减去这两个数的和简算;
②运用乘法分配律简算;
③先算除法,再算乘法,然后算减法.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.