In a math competition, there are 20 questions in total. For each correct answer, 5 points will be awarded, and 1 point will be deducted for wrong answers. Xiaohua will get 70 points. How many questions did he answer correctly?
在一次数学竞赛中共有20道题，每做对一题得5分，做错或不做扣1分，小华得了70分，他共做对了几道题？
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

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

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<result>15</result>