Mr. Li likes calligraphy, and practice pen calligraphy and brush calligraphy every day. He has to practice 100 pen characters every day, which is exactly 4 times that of brush characters. How many characters does Mr. Li practice every day?
李老师爱好书法，天天练钢笔字和毛笔字．他每天要练100个钢笔字，正好是毛笔字的4倍．李老师每天一共要练多少个字？
<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">100 + 25</gadget>
<output>125</output>

<result>125</result>