Each grid on graph paper represents 1 square centimeter, and an irregular figure contains 46 full grids and 24 sub-full grids. What is the approximate area of this irregular figure in square centimetres?
方格纸上每个方格表示1平方厘米，一个不规则的图形一共包含46个整格和24个不满整格．这个不规则图形的面积大约是多少平方厘米．
<gadget id="calculator">46 * 1</gadget>
<output>46</output>

<gadget id="calculator">0.5 * 24</gadget>
<output>12</output>

<gadget id="calculator">46 + 12</gadget>
<output>58</output>

<result>58</result>