Thirty-six marbles are divided between Mario and Manny in the ratio 4:5. If Manny decided to give 2 marbles to his brother, how many marbles does Manny have now?
The marbles are divided into 4 + 5 = 
<gadget id="calculator">4+5</gadget>
<output>9</output>
9 parts.
Each part consists 36/9 = 
<gadget id="calculator">36/9</gadget>
<output>4</output>
4 marbles.
So Manny had 5 parts x 4 = 
<gadget id="calculator">5*4</gadget>
<output>20</output>
20 marbles.
After giving 2 marbles to his brother, he now has 20 - 2 = 
<gadget id="calculator">20-2</gadget>
<output>18</output>
18 marbles left.

<result>18</result>