The number of black rabbits raised by Grandpa Zhang is 90% of that of white rabbits. If the number of black rabbits is increased by 20%, will there be more white rabbits or more black rabbits? How much?
张爷爷养的黑兔只数是白兔的90%，如果把黑兔只数增加20%，那么白兔多还是黑兔多？多多少？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 * (9/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(9/10) * (6/5)</gadget>
<output>27/25 = around 1.08</output>

<gadget id="calculator">(27/25) - 1</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">(2/25) / 1</gadget>
<output>2/25 = around 0.08</output>

<result>2/25 = around 0.08</result>