If you buy 6 notebooks and 2 counting herbs, you will get 2.70 yuan, and if you buy 2 notebooks and 6 counting herbs, you will pay 1.70 yuan. How much is a notebook?
买6个笔记本和2个算草本共用去2.70元，买2个笔记本和6个算草本共用去1.70元，求一个笔记本多少元．
<gadget id="calculator">2.7 + 1.7</gadget>
<output>4.4</output>

<gadget id="calculator">2 + 6</gadget>
<output>8</output>

<gadget id="calculator">4.4 / 8</gadget>
<output>0.55</output>

<gadget id="calculator">0.55 * 2</gadget>
<output>1.1</output>

<gadget id="calculator">2.7 - 1.1</gadget>
<output>1.6</output>

<gadget id="calculator">6 - 2</gadget>
<output>4</output>

<gadget id="calculator">1.6 / 4</gadget>
<output>0.4</output>

<result>0.4</result>