题目内容
1.25+2.25+3.25+4.25+5.25+…+50.25．
分析：据观察，每个小数都含有0.25，因此，把每个数拆成“整数+0.25”的形式，然后把整数与小数分别相加，整数部分运用求和公式计算，小数部分用乘法计算．
解答：解：1.25+2.25+3.25+4.25+5.25+…+50.25
=（1+2+3+4+5+…+50）+0.25×50
=（1+50）×50÷2+12.5
=51×50÷2+12.5
=1275+12.5
=1287.5
=（1+2+3+4+5+…+50）+0.25×50
=（1+50）×50÷2+12.5
=51×50÷2+12.5
=1275+12.5
=1287.5
点评：注意观察题目中数字构成的特点和规律，通过拆分，善于灵活运用运算技巧，巧妙解答．
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