Xiao Ming read 90 pages today, and the number of pages he read yesterday was less than today (1/9). Question: How many pages did Xiao Ming read yesterday?
小明今天看书90页，昨天看书的页数比今天少(1/9)．问：小明昨天看书多页？
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 - (1/9)</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">90 * (8/9)</gadget>
<output>80</output>

<result>80</result>