Grandma Zhang loves calligraphy, and she insists on writing 30 brush characters every day. According to this calculation, how many brush characters did she write in May this year?
张奶奶爱好书法，她每天坚持写30个毛笔字．照这样计算，今年五月份她一共写了多少个毛笔字？
<gadget id="calculator">30 * 31</gadget>
<output>930</output>

<result>930</result>