The radius of a coin is $$3\text{cm}$$. When $$4000$$ of these coins are placed side by side in a straight line, how long would this line be? 
Overseas Competition->Knowledge Point->Word Problem Modules->Unitary Method Problems->Finding the Total Value using Unitary Method
The length of the line is $$4000\times 2\times 3\text{cm=}24000\text{cm=}240\text{m}$$. 