Class 601 planted 45 trees in the "Thanksgiving Nature" tree planting activity, and 5 trees died. Later, 5 trees were replanted, and all survived. What is the survival rate?
601班在"感恩大自然"植树活动中，种了45棵，死了5棵，后来又补种5棵，全部成活，成活率是多少．
<gadget id="calculator">45 - 5</gadget>
<output>40</output>

<gadget id="calculator">40 + 5</gadget>
<output>45</output>

<gadget id="calculator">45 + 5</gadget>
<output>50</output>

<gadget id="calculator">45 / 50</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(9/10) * 1</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>