不知您有沒有仔細觀察過我們天天使用的電話：它的按鍵排列，0是在最下方的。不是應該越小的數字越應該排在前面嗎？為什么電話的按鍵布局這么特別呢？下面這篇文章就將為您解釋這個問題。

    Mechanical adding machines, based on rotating wheels, always have the 0 button adjacent to the 1 button. By convention, most old adding machines had the numbers increasing in value from the bottom. When the numbers were put onto a pad arranged as a 3 by 3 grid with one left over, the order of the numbers was kept the same.

    On a rotary telephone dial, the 0 comes adjacent to the 9 because a 0 in the telephone number is signaled by 10 pulses on the line. When telephones acquired push buttons in a grid, the ordering of the buttons was carried over from the old telephone dial.

    adjacent: 鄰近的