Obviously, the average score of the first two long jumps is 120 cm, and after the third test, the average score of the three tests is 123 cm, so how many centimeters did he jump for the third time?
明明前两次跳远的平均成绩是120厘米，第三次测验后，三次测验的平均成绩是123厘米，那么他第三次跳了多少厘米？
<gadget id="calculator">123 * 3</gadget>
<output>369</output>

<gadget id="calculator">120 * 2</gadget>
<output>240</output>

<gadget id="calculator">369 - 240</gadget>
<output>129</output>

<result>129</result>