Andy harvests all the tomatoes from 18 plants that have 7 tomatoes each. If he dries half the tomatoes and turns a third of the remainder into marinara sauce, how many tomatoes are left?
First find the total number of tomatoes harvested: 18 plants * 7 tomatoes/plant = 
<gadget id="calculator">18*7</gadget>
<output>126</output>
126 tomatoes.
Then divide that number by 2 to find how many tomatoes are left undried: 126 tomatoes / 2 = 
<gadget id="calculator">126/2</gadget>
<output>63</output>
63 tomatoes.
Then divide that number by 3 to find how many tomatoes are turned into sauce: 63 tomatoes / 3 = 
<gadget id="calculator">63/3</gadget>
<output>21</output>
21 tomatoes.
Then subtract that number from the number of undried tomatoes to find the remaining number of tomatoes: 63 tomatoes - 21 tomatoes = 
<gadget id="calculator">63-21</gadget>
<output>42</output>
42 tomatoes.

<result>42</result>