The students of Qianlou Central Primary School used Sunday to collect tree species. They collected 2.8 kilograms in the first week, which was 0.13 kilograms more than in the second week. How many kilograms did they collect in two weeks?
前楼中心小学的同学利用周日采集树种，第一周采集2.8千克，比第二周的多0.13千克，两周一共采集了多少千克？
<gadget id="calculator">2.8 - 0.13</gadget>
<output>2.67</output>

<gadget id="calculator">2.8 + 2.67</gadget>
<output>5.47</output>

<result>5.47</result>