I thought of a number y in my heart, multiply this number by 4, add 6, and then subtract 3 to get 87. y = how much.
我心里想了一个数y，这个数乘4，加上6，再减去3，得87．y=多少．
<gadget id="calculator">87 - 3</gadget>
<output>84</output>

<gadget id="calculator">84 / 4</gadget>
<output>21</output>

<result>21</result>