Try it Live

<!DOCTYPE html>
<html>
 <head>
  <style>
  .flexbox-container17a {
    margin:10px;
    background-color: yellow;
    width:300px;
    height: 500px;
    display: flex;
    flex-wrap:wrap;
  }
  
  .flexbox-container17aa {
    margin:10px;
    background-color: yellow;
    height: 500px;
    display: flex;
    width:300px;
    flex-wrap:wrap;
    align-content:space-around;
  }
  
  .child-items3a {
    padding: 25px 0;
    margin: 5px;
    width:60px;
    height:80px;
    text-align: center;
    border:1px solid olive;
    background-color: tomato;
  }
  </style>
 </head>
 <body>
 
 <h4>Without align-content: space-around</h4>
  <div class="flexbox-container17a">
     <div class="child-items3a">Item 1</div>
     <div class="child-items3a">Item 2</div>
     <div class="child-items3a">Item 3</div>
     <div class="child-items3a">Item 4</div>
     <div class="child-items3a">Item 5</div>
     
  </div>
  
  <h4>With align-content: space-around</h4>
  <div class="flexbox-container17aa">
     <div class="child-items3a">Item 1</div>
     <div class="child-items3a">Item 2</div>
     <div class="child-items3a">Item 3</div>
     <div class="child-items3a">Item 4</div>
     <div class="child-items3a">Item 5</div>
     
  </div>
 </body>
</html>

​x
 
<!DOCTYPE html>
<html>
 <head>
  <style>
  .flexbox-container17a {
    margin:10px;
    background-color: yellow;
    width:300px;
    height: 500px;
    display: flex;
    flex-wrap:wrap;
  }
  
  .flexbox-container17aa {
    margin:10px;
    background-color: yellow;
    height: 500px;
    display: flex;
    width:300px;
    flex-wrap:wrap;
    align-content:space-around;
  }
  
  .child-items3a {
    padding: 25px 0;
    margin: 5px;
    width:60px;
    height:80px;
    text-align: center;
    border:1px solid olive;
    background-color: tomato;
  }
  </style>
 </head>
 <body>
 
 <h4>Without align-content: space-around</h4>
  <div class="flexbox-container17a">
     <div class="child-items3a">Item 1</div>
     <div class="child-items3a">Item 2</div>
     <div class="child-items3a">Item 3</div>
     <div class="child-items3a">Item 4</div>
     <div class="child-items3a">Item 5</div>
     
  </div>
  
  <h4>With align-content: space-around</h4>
  <div class="flexbox-container17aa">
     <div class="child-items3a">Item 1</div>
     <div class="child-items3a">Item 2</div>
     <div class="child-items3a">Item 3</div>
     <div class="child-items3a">Item 4</div>
     <div class="child-items3a">Item 5</div>
     
  </div>
 </body>
</html>
​