There are 7 pencil drawings, 7 crayon drawings, and 7 watercolor paintings. How many drawings are there in total?
铅笔画有7张，蜡笔画有7张，水彩画也有7张，一共有多少张画？
<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<result>21</result>