(1)98.56-(8.56-3.28)(2)×52(3)4.9×3.8+7.2×4.9-4.9(4)+(-)÷(5)(-)÷(+)
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解:(1)98.56-(8.56-3.28),
=98.56-8.56+3.28,
=90+3.28,
=93.28;
(2)×52,
=×(51+1),
=×51+×1,
=50+,
=50;
(3)4.9×3.8+7.2×4.9-4.9,
=4.9×(3.8+7.2-1),
=4.9×10,
=49;
(4)+(-)÷,
=+÷,
=+,
=1;
(5)(-)÷(+),
=÷,
=.
解析分析:(1)先去括号,然后再计算;由于括号外的符号是减号,去括号时括号里面的运算符合要改变;
(2)把52分解成51+1,然后运用乘法分配律简算;
(3)运用乘法分配律简算;
(4)先算小括号里面的减法,再算括号外的除法,最后算加法;
(5)先同时运算小括号里面的减法和加法,再算括号外的除法.
点评:此题主要考查小数、分数的四则混合运算的运算顺序和应用运算定律进行简便计算.