Dean has 30 marbles. He gives 1/5  of them to Jamie and gives 10 to Donald. How many marbles are left for Dean?
Dean gives 30 x 1/5 = 
<gadget id="calculator">30*1/5</gadget>
<output>6</output>
6 marbles to Jamie.
He gives a total of 6 + 10 = 
<gadget id="calculator">6+10</gadget>
<output>16</output>
16 marbles in all.
So, Dean has 30 - 16 = 
<gadget id="calculator">30-16</gadget>
<output>14</output>
14 marbles left.

<result>14</result>