Xiao Ming bought 4 story books and 4 science books each, paid 20 yuan, and got back 5.2 yuan. It is known that each technical book is 2.2 yuan. How much is each storybook?
小明买故事书和科技书各4本，付出20元，找回5.2元．已知每本科技书2.2元．每本故事书多少钱？
<gadget id="calculator">4 * 2.2</gadget>
<output>8.8</output>

<gadget id="calculator">20 - 8.8 - 5.2</gadget>
<output>6</output>

<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>