There are 10 questions in a math competition. It is stipulated that if you answer a question correctly, you will get 10 points, and if you get a wrong question, 3 points will be deducted. Xiao Ming has done all of them, but he only gets 61 points. So how many questions did Xiao Ming get wrong?
一次数学竞赛共10题，规定做对一题得10分，做错一题倒扣3分，小明都做了，但只得到分61分，那么小明做错多少题．
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">100 - 61</gadget>
<output>39</output>

<gadget id="calculator">10 + 3</gadget>
<output>13</output>

<gadget id="calculator">39 / 13</gadget>
<output>3</output>

<result>3</result>