It is known that the trees of a small group of species account for (2/5) of the total number, and the trees of the second group of species account for (1/3) of the total number. Comparing groups 1 and 2, which group planted more trees? How much?
已知一小组种的树占总数的(2/5)，二小组种的树占总数的(1/3)．一、二小组相比较，哪个小组种的树多？多多少？
<gadget id="calculator">6 / 15</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">5 / 15</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<result>1/15 = around 0.066667</result>