Xiao Hua drew a line segment 6 cm long, and Xiao Lin drew a line segment 3 cm long. How many centimeters longer the line segment drawn by Xiao Hua is 4 times the length of the line segment drawn by Xiao Lin.
小华画了一条6厘米长的线段，小林画了一条3厘米长的线段．小华画的线段再长多少厘米就是小林画的线段长度的4倍．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">12 - 6</gadget>
<output>6</output>

<result>6</result>