A wire uses up (3/10) decimeters and leaves (7/10) decimeters. How many centimeters was this wire originally?
一根电线，用去(3/10)分米，还剩(7/10)分米，这根电线原来长几厘米？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(3/10) + (7/10)</gadget>
<output>1</output>

<gadget id="calculator">1 * 10</gadget>
<output>10</output>

<result>10</result>