问题 解答题

计算:12.34+23.45+34.56+45.67+56.78+67.89+78.91+89.12+91.23.

答案

12.34+23.45+34.56+45.67+56.78+67.89+78.91+89.12+91.23

=11.11×(1+2+…+8+9),

=11.11×45,

=499.95.

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