Teacher Lin has to give art classes to 3 classes every day, and the number of students in each class is between 42-46. How many students does Mr. Lin teach every day?
林老师每天要给3个班上美术课，每个班同学人数都在42-46之间．林老师每天大约要给多少名学生上课多少人
<gadget id="calculator">40 * 3</gadget>
<output>120</output>

<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<gadget id="calculator">120 - 150</gadget>
<output>-30</output>

<result>-30</result>