((1234567891**2-1234567890*1234567892)/(1+2+3+4+...+99+100+99+...+4+3+2+1))=how much.
((1234567891**2-1234567890*1234567892)/(1+2+3+4+…+99+100+99+…+4+3+2+1))=多少．
<gadget id="calculator">1_234_567_891 ** 2</gadget>
<output>1_524_157_877_488_187_881</output>

<gadget id="calculator">1_234_567_890 * 1_234_567_892</gadget>
<output>1_524_157_877_488_187_880</output>

<gadget id="calculator">1_524_157_877_488_187_881 - 1_524_157_877_488_187_880</gadget>
<output>1</output>

<gadget id="calculator">50 * 100</gadget>
<output>5_000</output>

<gadget id="calculator">5_000 + 50</gadget>
<output>5_050</output>

<gadget id="calculator">49 * 100</gadget>
<output>4_900</output>

<gadget id="calculator">4_900 + 50</gadget>
<output>4_950</output>

<gadget id="calculator">5_050 + 4_950</gadget>
<output>10_000</output>

<gadget id="calculator">1 / 10_000</gadget>
<output>1/10_000 = around 0.0001</output>

<result>1/10_000 = around 0.0001</result>