How to fetch div value with specific id using Jquery?

I have list of data with add button . On button click how to get value of div with id="rnumber" with jquery .i want number on button click. i don't know how to get that number i try but every time i get first number of list i want number of same class . ex. if i click on second li button still i get first li class div value . I try with parents and child selector but i don't get anwser.

<div class="modal-body">
    <ul class="searchresult" style="list-style-type: none;">
        <li>
            <div  class="kt-font-lg">AKash</div>
            <div  class="kt-font-lg rnumber" >1234567890</div>
            <button  class="kt-font-lg btn-primary " onclick="addNumber()">Add</button>
        </li>
        <li>
            <div  class="kt-font-lg">Deep</div>
            <div  class="kt-font-lg rnumber" >9012345678</div>
            <button  class="kt-font-lg btn-primary " onclick="addNumber()">Add</button>
        </li>
    </ul>
</div>

onClick function :

function addNumber(){
                rnumber = $('#rnumber');
                var  ttt = rnumber.text();
                console.log(ttt);        
             }

You have to keep your IDs unique. Duplicating IDs is a crime. Change it to a class instead. Since multiple elements share the same function, use event.target or this. You can use something like this:

function addNumber() {
  console.log($(event.target).prev().text());
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="modal-body">
  <ul class="searchresult" style="list-style-type: none;">
    <li>
      <div class="kt-font-lg">AKash</div>
      <div class="kt-font-lg rnumber">1234567890</div>
      <button class="kt-font-lg btn-primary" onclick="addNumber()">Add</button>
    </li>
    <li>
      <div class="kt-font-lg">Deep</div>
      <div class="kt-font-lg rnumber">9012345678</div>
      <button class="kt-font-lg btn-primary" onclick="addNumber()">Add</button>
    </li>
  </ul>
</div>

In a better way, use unobtrusive JavaScript event handling:

$(function () {
  $(".btn-primary").click(function () {
    console.log($(this).prev().text());
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="modal-body">
  <ul class="searchresult" style="list-style-type: none;">
    <li>
      <div class="kt-font-lg">AKash</div>
      <div class="kt-font-lg rnumber">1234567890</div>
      <button class="kt-font-lg btn-primary">Add</button>
    </li>
    <li>
      <div class="kt-font-lg">Deep</div>
      <div class="kt-font-lg rnumber">9012345678</div>
      <button class="kt-font-lg btn-primary">Add</button>
    </li>
  </ul>
</div>