Question

如何用简便方法计算1.2+1.3+1.4+1.5？

Answer 1

1.2+1.3+1.4+1.5计算方法

=(1.2+1.3)+1.5+1.4

=2.5+1.5+1.4

=4+1.4

=5.4

Answer 2

1.2+1.3+1.4+1.5计算过程
=2.5+1.5+1.4
=4+1.4
=5.4

Answer 3

1.2十1.3十1.4十1.5
=2.5十1.5十1.4
=4十1.4
=5.4

Answer 4

简算
原式=6/7
解题分析
将分母6、12、20、30、42分解为2×3、3×4、4×5、5×6、6×7，然后再化简。
1/2+1/6+1/12+1/20+1/30+1/42
=1/2+1/（2×3）+1/（3×4）+1/（5×6）+1/（6×7）
=1/2+（1/2-1/3）+（1/3-1/4）+（1/5-1/6）+（1/6-1/7）
=1/2+1/2-1/7
=1-1/7
=6/7

Answer 5

=(1.2+1.3+1.5)+1.4
=4+1.4
=5.5