"June 1st" is here, Guangming Experimental Primary School will give each student a piece of food, each food is 10 yuan, 10% off at Macro Supermarket; Dragon Boat Shopping Plaza "buy 8 get 1 free"; Jufu Department Store buys over 1,000 yuan, 150 yuan off For the portion exceeding 1,000 yuan, it will be calculated by subtracting 100 yuan for every increase of 1,000 yuan. The school wants to buy 1,800 food items, please do the math: Which one is more cost-effective to buy? Please write down your calculation process.
"六一"到了，光明实验小学要给每个学生一份食品，每份食品10元，万家乐超市打九折；龙舟购物广场"买八送一"；聚福百货买满1000元，减150元，超过1000元部分，按每增加1000元，再减100元计算．学校想买1800份食品，请你算一算：到哪家购买较合算？请写出你的计算过程．
<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">1_800 * (8/9) * 10</gadget>
<output>16_000</output>

<result>16_000</result>