124.68+324.68+524.68+724.68+924.68怎样计算?

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124.68+324.68+524.68+724.68+924.68怎样计算?

124.68+324.68+524.68+724.68+924.68怎样计算?
124.68+324.68+524.68+724.68+924.68怎样计算?

124.68+324.68+524.68+724.68+924.68怎样计算?
计算器杠上、

124.68+324.68+524.68+724.68+924.68
=100+300+500+700+900+24.68×5
=2500+123.4
=2623.4

先算百位,1+3+5+7+9=25,也就是2500
再算后面的24*5=120
最后算分数0.68*5=3.4
把这三个数相加:2623.4

其中运用了拆分数,乘法是加法的简便运算,特殊数据的求和公式:(a1+an)×n÷2
124.68+324.68+524.68+724.68+924.68
=100+24.68+300+24.68+500+24.68+700+24.68+900+24.68
=100+300+500+700+900+24.68×5
=(100+900)×5÷2+123.4
=2500+123.4
=2623.4