The leader of the sheep asked the lambs to harvest 2,730 kilograms of green grass on the orangutan grassland. The 8 sheep harvested 480 kilograms of green grass in 4 days, and the rest of the requirements were completed in 10 days. In the case of the same work efficiency, how many lambs need to be added?
羊头领让小羊们到猩猩草原上收割2730千克青草，8只羊4天收割了480千克青草，余下的要求在10天完成．在工作效率相同的情况下，需要增加小羊多少只？
<gadget id="calculator">2_730 - 480</gadget>
<output>2_250</output>

<gadget id="calculator">480 / 4 / 8</gadget>
<output>15</output>

<gadget id="calculator">2_250 / 10 / 15</gadget>
<output>15</output>

<gadget id="calculator">15 - 8</gadget>
<output>7</output>

<result>7</result>