Mary is an avid gardener. Yesterday, she received 18 new potted plants from her favorite plant nursery. She already has 2 potted plants on each of the 40 window ledges of her large country home. Feeling generous, she has decided that she will give 1 potted plant from each ledge to friends and family tomorrow. How many potted plants will Mary remain with?
Yesterday, before receiving the plants, Mary had 2*40 = 
<gadget id="calculator">2*40</gadget>
<output>80</output>
80 potted plants.
After receiving an additional 18 plants, she therefore had a total of 80 + 18 = 
<gadget id="calculator">80+18</gadget>
<output>98</output>
98 potted plants.
Tomorrow, Mary's plant giveaway will be 40 *1 = 
<gadget id="calculator">40*1</gadget>
<output>40</output>
40 potted plants.
She will therefore remain with 98 - 40 = 
<gadget id="calculator">98-40</gadget>
<output>58</output>
58 potted plants.

<result>58</result>