Add 1 to a certain number, subtract 2, multiply by 3, divide by 4 to get 9, find this number.
某数加上1，减去2，乘以3，除以4得9，求这个数．
<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">9 * (4/3)</gadget>
<output>12</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">12 + 1</gadget>
<output>13</output>

<result>13</result>