The total score of Xiao Ming's Chinese and mathematics is 180, and his science score is 57. What is his average score?
小明语文、数学两门功课总分是180分，科学是57分，他的平均成绩是多少分．
<gadget id="calculator">180 + 57</gadget>
<output>237</output>

<gadget id="calculator">237 / 3</gadget>
<output>79</output>

<result>79</result>