2.1xx=36.7+29.3．
2.1x-x=36.7+29.3．
<gadget id="calculator">36.7 + 29.3</gadget>
<output>66</output>

<gadget id="calculator">2.1 - 1</gadget>
<output>1.1</output>

<gadget id="calculator">66 / 1.1</gadget>
<output>60</output>

<result>60</result>