In a subtraction formula, the minuend is reduced by 27, and the subtrahend remains unchanged, how much is the difference.
在一道减法算式中，被减数减少27，减数不变，差多少．
<gadget id="calculator">100 - 30</gadget>
<output>70</output>

<gadget id="calculator">73 - 30</gadget>
<output>43</output>

<gadget id="calculator">70 - 43</gadget>
<output>27</output>

<result>27</result>