When the little sloppy calculated the addition problem, he mistakenly regarded 5.7 as 57 and calculated the result as 72.4. What should be the correct result?
小马虎计算加法题时，错把5.7看成57计算得结果是72.4，正确的结果应该是多少？
<gadget id="calculator">72.4 - 57</gadget>
<output>15.4</output>

<gadget id="calculator">15.4 + 5.7</gadget>
<output>21.1</output>

<result>21.1</result>