The sum of the numbers A and B is 55.4, and the number A is 5.4 less than the number B. What is the number of armor?
甲、乙两数的和是55.4，甲数比乙数小5.4．甲数是多少？
<gadget id="calculator">55.4 - 5.4</gadget>
<output>50</output>

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

<gadget id="calculator">50 / 2</gadget>
<output>25</output>

<result>25</result>