Mr. Wang bought prizes. He bought 28 notebooks at 2.5 yuan each and 36 pens at 3.2 yuan each. How much less does the book cost than the pen?
王老师买奖品，每本2.5元的本子买了28本，每枝3.2元的钢笔买了36枝．本子比钢笔共少花多少钱？
<gadget id="calculator">3.2 * 36</gadget>
<output>115.2</output>

<gadget id="calculator">2.5 * 28</gadget>
<output>70</output>

<gadget id="calculator">115.2 - 70</gadget>
<output>45.2</output>

<result>45.2</result>