Mary has 5 green crayons and 8 blue crayons of different shades. If she gives out 3 green crayons and 1 blue crayon to Becky, how many crayons does she have left?
She had 5+8 = 
<gadget id="calculator">5+8</gadget>
<output>13</output>
13 crayons to start with.
She gave out 3+1 = 
<gadget id="calculator">3+1</gadget>
<output>4</output>
4 crayons to Becky.
She will have 13-4 = 
<gadget id="calculator">13-4</gadget>
<output>9</output>
9 crayons left.

<result>9</result>