In a vegetable field, the cucumber field accounts for 40% of the total area, and the radish field accounts for 30% of the total area. What is the total area of the cucumber field and the radish field?
一片菜地，黄瓜地占总面积的40%，萝卜地占总面积的30%，黄瓜地和萝卜地菜占总面积的多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(2/5) + (3/10)</gadget>
<output>7/10 = around 0.7</output>

<result>7/10 = around 0.7</result>