Sean needs to replace 2 light bulbs in his bedroom, 1 in both the bathroom and the kitchen and 4 in the basement.  He also needs to replace 1/2 of that amount in the garage.  The bulbs come 2 per pack.  How many packs will he need?
He needs to replace lights in the bedroom, bathroom, kitchen and basement so 2+1+1+4 = 
<gadget id="calculator">2+1+1+4</gadget>
<output>8</output>
8 lightbulbs.
In the garage, he needs to replace half that amount so he needs 8/2 = 
<gadget id="calculator">8/2</gadget>
<output>4</output>
4 lightbulbs.
All total, he needs 8+4 = 
<gadget id="calculator">8+4</gadget>
<output>12</output>
12 light bulbs.
They come 2 per pack and he needs 12 lightbulbs so he needs 12/2 = 
<gadget id="calculator">12/2</gadget>
<output>6</output>
6 packs of lightbulbs.

<result>6</result>