Grandma Wang went to the supermarket and bought 2.5 kilograms of spinach, which cost 4.5 yuan. What is the price of 1 kilogram of spinach?
王奶奶去超市，买了2.5千克菠菜，花了4.5元钱，1千克菠菜的价格是多少元．
<gadget id="calculator">4.5 / 2.5</gadget>
<output>1.8</output>

<result>1.8</result>