83+84+85+86+87+88+89怎样算最简便

分类: 作业答案 • 2022-02-14 14:04:53

问题描述：

答

用计算机算，最简便

答

83+84+85+86+87+88+89
=86*7
=602

答

83+84+85+86+87+88+89
=83+3+84+2+85+1+86+87-1+88-2+89-3
=86+86+86+86+86+86+86
=86x7
=80x7+6x7
=560+42
=602

答

83+84+85+86+87+88+89
=(83+89)+(84+88)+(85+87)+86
=7*86
=7*80+7*6
=560+42
=602