1999/(1999+(1999/2000))+(1/2000).
1999/(1999+(1999/2000))+(1/2000)．
<gadget id="calculator">1_999 / 2_000</gadget>
<output>1_999/2_000 = around 0.9995</output>

<gadget id="calculator">1_999 + (1_999/2_000)</gadget>
<output>3_999_999/2_000 = around 1_999.9995</output>

<gadget id="calculator">1_999 / (3_999_999/2_000)</gadget>
<output>2_000/2_001 = around 0.9995</output>

<gadget id="calculator">1 / 2_000</gadget>
<output>1/2_000 = around 0.0005</output>

<gadget id="calculator">(2_000/2_001) + (1/2_000)</gadget>
<output>4_002_001/4_002_000 = around 1</output>

<result>4_002_001/4_002_000 = around 1</result>