A sixth-grade student of Chongtou Primary School picked rice ears. Class 61 picked up 254 kilograms; Class 62 was divided into 4 groups, each group picked up an average of 68 kilograms. Which class picked up the most ears of rice? How many kilograms?
冲头小学六年级同学捡稻穗．六一班捡了254千克；六二班分成4组，平均每组捡了68千克．哪个班捡的稻穗多？多少千克？
<gadget id="calculator">4 * 68</gadget>
<output>272</output>

<gadget id="calculator">272 - 254</gadget>
<output>18</output>

<result>18</result>