It takes 1 hour for refrigerated dough to come to room temperature.  It takes 15 minutes to shape the dough and 2 hours to proof.  The bread takes 30 minutes to bake and 15 minutes to cool.  If the bakery opens at 6:00 am, what is the latest time the head baker can make it to the store to start working?
It takes 1 hour to bring the dough to room temp and 2 hours to proof the dough so that's 1+2 = 
<gadget id="calculator">1+2</gadget>
<output>3</output>
3 hours.
It takes 15 minutes to shape the dough, 30 minutes to bake and another 15 minutes to cool for a total of 15+30+15 = 
<gadget id="calculator">15+30+15</gadget>
<output>60</output>
60 minutes.
There are 60 minutes in 1 hour so that takes him 60/60 = 
<gadget id="calculator">60/60</gadget>
<output>1</output>
1 hour.
In total it takes 3+1 = 
<gadget id="calculator">3+1</gadget>
<output>4</output>
4 hours from start to finish to make the bread.
If the bakery opens at 6:00 am and it takes 4 hours to prep then the latest the head baker can show up is 6-4 = 
<gadget id="calculator">6-4</gadget>
<output>2</output>
2:00 am.

<result>2</result>