Plant saplings on an open space with a length of 20 meters and a width of 16 meters. On average, one sapling is planted every 4 square meters. How many saplings can be planted in total?
在一块长20米、宽16米的空地上栽树苗，平均每4平方米栽一棵树苗，一共可以栽多少棵树苗？
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>