The sum of the number A and the number B is 2880, and the number B is 1800. What is the number A?
甲数与乙数的和是2880，乙数是1800，甲数是多少？
<gadget id="calculator">2_880 - 1_800</gadget>
<output>1_080</output>

<result>1_080</result>