Cut a piece of cake into 7 pieces on average, Xiaohong ate 4 pieces, how much did he eat from this piece of cake?
把一块蛋糕平均切成7块小红吃了4块，吃了这块蛋糕的多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<result>4/7 = around 0.571429</result>