脱式计算(能简算的要简算)(1)4.65-1.55-1.45 (2)58.1-29.7÷3 (3)201×3.5-3.5
1个回答

解题思路:(1)运用减法的性质简算;

(2)先算出发,再算剑法;

(3)(4)运用乘法分配律简算.

(1)4.65-1.55-1.45,

=4.65-(1.55+1.45),

=4.65-3,

=1.65;

(2)58.1-29.7÷3,

=58.1-9.9,

=58.1-(10-0.1),

=58.1-10+0.1,

=48.2;

(3)201×3.5-3.5,

=(201-1)×3.5,

=200×3.5,

=700;

(4)2.2×0.25+0.25×1.8,

=(2.2+1.8)×0.25,

=4×0.25,

=1.

点评:

本题考点: 整数、分数、小数、百分数四则混合运算;运算定律与简便运算.

考点点评: 考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律简算.