A small tree is 2 meters high this year, and it will be 8 meters high in 4 years. How many meters does this tree grow each year on average?
一棵小树今年有2米高，再过4年以后有8米高，这棵树平均每年长多少米？
<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>