A pencil is 2.5 yuan, which is 0.7 yuan more expensive than an eraser. How much is an eraser?
一枝铅笔2.5元，比一块橡皮擦贵0.7元，一块橡皮擦多少元．
<gadget id="calculator">2.5 - 0.7</gadget>
<output>1.8</output>

<result>1.8</result>