It is known that the sum of two numbers is 85.7, and one of the addends is 15.7, what is the other addend?
已知两个数的和是85.7，其中一个加数是15.7，求另一个加数是多少？
<gadget id="calculator">85.7 - 15.7</gadget>
<output>70</output>

<result>70</result>