There are 10 questions in a certain mathematics competition, 10 points are awarded for each correct answer, and 5 points are deducted for each wrong answer. Xiaojun got 70, how many questions did he answer correctly.
某次数学竞赛共10道题，答对一题得10分，答错一题扣5分．小军得了70，他答对了多少道题．
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">100 - 70</gadget>
<output>30</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">30 / 15</gadget>
<output>2</output>

<gadget id="calculator">10 - 2</gadget>
<output>8</output>

<result>8</result>