If the outer circumference of a ring is 15.7cm and the inner circumference is 9.42cm, what is the width of the ring in cm?
一个圆环的外圆周长是15.7cm，内圆周长为9.42cm，则这个圆环的宽度是多少cm．
<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<gadget id="calculator">9.42 / 3.14 / 2</gadget>
<output>1.5</output>

<gadget id="calculator">2.5 - 1.5</gadget>
<output>1</output>

<result>1</result>