The First Machine Tool Factory produces 891 machine tools this year, an increase of 10% over last year. How much is this year's increase over last year?
第一机床厂，今年生产机床891台，比去年增产10%，今年比去年增产多少台？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">891 / (11/10)</gadget>
<output>810</output>

<gadget id="calculator">891 - 810</gadget>
<output>81</output>

<result>81</result>