Xiao Ming buys 8 Chinese texts for 12 yuan, and buys 5 math books for 9 yuan. On average, how much is each Chinese text cheaper than the math book?
小明买8本语文本共用去12元，买5本数学本共用去9元，平均每本语文本比数学本便宜多少元？
<gadget id="calculator">9 / 5</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">12 / 8</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(9/5) - (3/2)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>