fifty的记忆方法：有five演变而来
例句
1、
Around fifty people die of hunger every day in the camp.
集中营里每天大约有五十人饿死。
2、
To look at him you'd never think he was nearly fifty.
看他的外表，谁也想不到他年近五十了。
3、
He's ancient ─ he must be at least fifty!
他老得很了——肯定至少有五十岁！
