Wang Xiaodou bought some assorted candies made from a mixture of sugars A and B, of which sugar A accounted for 45% of the total sugar. Later he bought another 16 pieces of sugar B, and it turned out that sugar A accounted for 45% of the total sugar. 25%, ask how many pieces of sugar Wang Xiaodou bought?
王小豆买了一些由甲、乙两种糖混合而成的什锦糖，其中甲种糖占全部糖的45%，后来他又买进了16块乙种糖，结果甲种糖占全部糖的25%，问王小豆买了多少块甲种糖？
<gadget id="calculator">100 / 25</gadget>
<output>4</output>

<gadget id="calculator">100 / 45</gadget>
<output>20/9 = around 2.222222</output>

<gadget id="calculator">4 - (20/9)</gadget>
<output>16/9 = around 1.777778</output>

<gadget id="calculator">16 / (16/9)</gadget>
<output>9</output>

<result>9</result>