There are two ways to buy a house: installment payment and one-time payment. The specific plan is as follows: overpay 16% of the total house price in installments, and enjoy a "five percent discount" discount on the total house price if you pay in one lump sum. Teacher Zhang is going to buy a house with a total price of 300,000. Could you help me figure it out, how much will it cost less to pay in one lump sum than to pay in installments?
买房有分期付款和一次性付清两种方式．具体方案如下：分期付款多付房价总数的16%，一次性付清享受房价总数的"九五折"优惠．张老师准备买一套总价为30万的住房．请你帮忙算算，用一次性付款要比分期付款少花多少钱？
<gadget id="calculator">16 / 100</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">95 / 100</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">(4/25) - (19/20)</gadget>
<output>-79/100 = around -0.79</output>

<gadget id="calculator">1 + (-79/100)</gadget>
<output>21/100 = around 0.21</output>

<gadget id="calculator">30 * (21/100)</gadget>
<output>63/10 = around 6.3</output>

<result>63/10 = around 6.3</result>