Xiao Ming's average score in the previous math tests was 80. If he scored 100 in the latest test, his average score would increase to 84. So, how many times is the latest test?
小明前几次数学测验的平均分是80分，最近这次测验如果是100分，他的平均分就会提高到84分．那么，最近这次测验是第多少次．
<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">84 - 80</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>