The school carried out the activity of "collecting waste paper to promote environmental protection". The sixth grade students collected 55.6 kg of waste paper in October, 4.4 kg more than twice the amount collected by the first grade students. How many kg of waste paper did the first grade collect?
学校开展"收集废纸促环保"活动，六年级同学10月份收集废纸55.6千克，比一年级同学收集的2倍还多4.4千克，一年级收集废纸多少千克？
<gadget id="calculator">55.6 - 4.4</gadget>
<output>51.2</output>

<gadget id="calculator">51.2 / 2</gadget>
<output>25.6</output>

<result>25.6</result>