Zhang Ping and Wang Fang went to the store to buy pens together. Zhang Ping had 4 yuan left after buying the pen. Wang Fang borrowed 2 yuan from Zhang Ping to buy the pen. How much less money did Wang Fang bring than Zhang Ping.
张平与王芳一起到商店去买钢笔，张平买了笔后还剩4元，王芳向张平借了2元才够买笔，王芳所带的钱比张平少多少元．
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<result>6</result>