CSS

flex grow

#content {
  display: flex;

  justify-content: space-around;
  flex-flow: row wrap;
  align-items: stretch;
}

.box {
  flex-grow: 1;
  border: 3px solid rgba(0,0,0,.2);
}

.box1 {
  flex-grow: 2;
  border: 3px solid rgba(0,0,0,.2);
}

flex grow

.box-1{
    flex-grow: 1;
}
.box-2{
    flex-grow: 5;
}
.box-1{
    flex-grow: 1;
}

html flex grow

<h4>This is a Flex-Grow</h4>
<h5>A,B,C and F are flex-grow:1 . D and E are flex-grow:2 .</h5>
<div id="content">
  <div class="box" style="background-color:red;">A</div>
  <div class="box" style="background-color:lightblue;">B</div>
  <div class="box" style="background-color:yellow;">C</div>
  <div class="box1" style="background-color:brown;">D</div>
  <div class="box1" style="background-color:lightgreen;">E</div>
  <div class="box" style="background-color:brown;">F</div>
</div>

flex-grow css

flex-grow: <number>

/*example*/
.flex-item {
  flex-grow: 2;
}

flex grow

flex-grow: <number>

.flex-item {
  flex-grow: 2;
}

flex grow css

This property specifies how much of the remaining space in the flex container 
should be assigned to the item (the flex grow factor).