If Uncle Li buys a water heater, it will cost 1395 yuan if you buy a water heater with a 10% discount. If you buy a 20% discount, how much will it cost?
李大爷买热水器，如九折需花1395元，如果八折购买，需花多少钱？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1_395 / (9/10)</gadget>
<output>1_550</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1_550 * (4/5)</gadget>
<output>1_240</output>

<result>1_240</result>