The price of a set of "Fairy Tales" in the bookstore is as follows: 16 copies per set, 15.5 yuan each. Xiao Ming bought a set with his membership card, and only spent 198.4 yuan. How much money has he saved using his loyalty card?
书店一套《童话故事》标价如下：每套16本，每本15.5元．小明用会员卡买了一套，只用了198.4元．他使用会员卡节省了多少钱？
<gadget id="calculator">15.5 * 16</gadget>
<output>248</output>

<gadget id="calculator">248 - 198.4</gadget>
<output>49.6</output>

<result>49.6</result>