Grandpa bought a new mobile phone for 2,550 yuan, which is 15% cheaper than the original price. How much is it cheaper?
爷爷花2550元买了一部新手机，比原价便宜了15%，便宜了多少元钱？
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">2_550 / (17/20)</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 - 2_550</gadget>
<output>450</output>

<result>450</result>