At a certain school, 2/3 of the population are females. One-tenth of the males are foreign students. If the school has 300 students, how many students are non-foreign male students?
There are 300 x 2/3 = 
<gadget id="calculator">300*2/3</gadget>
<output>200</output>
200 females in the school.
So, 300 - 200 = 
<gadget id="calculator">300-200</gadget>
<output>100</output>
100 are males.
Out of the 100 males, 100 x 1/10 = 
<gadget id="calculator">100*1/10</gadget>
<output>10</output>
10 are male foreign students.
Thus, there are 100 - 10 = 
<gadget id="calculator">100-10</gadget>
<output>90</output>
90 non-foreign male students.

<result>90</result>