When making cakes in a certain shop, it is stipulated that 5 eggs should be added with 400 grams of flour, and the existing 15 eggs should be added with 1600 grams of flour. How many eggs do you need to add to meet the prescribed weight?
某店制蛋糕时规定5只鸡蛋加入400克面粉，现有鸡蛋15只加了面粉1600克．还需要加入几只鸡蛋才合乎规定的分量？
<gadget id="calculator">400 / 5</gadget>
<output>80</output>

<gadget id="calculator">1_600 / 80</gadget>
<output>20</output>

<gadget id="calculator">20 - 15</gadget>
<output>5</output>

<result>5</result>