The school organized third and fourth grade students to collect waste products. The third grade recycled 24.3 kg, 2.7 kg more than the fourth grade.
学校组织三、四年级学生收集废品，三年级回收了24.3千克，比四年级多回收了2.7千克，两个年级一共回收废品铁多少千克？
<gadget id="calculator">24.3 - 2.7</gadget>
<output>21.6</output>

<gadget id="calculator">21.6 + 24.3</gadget>
<output>45.9</output>

<result>45.9</result>