JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<div class="item item-custom-first">
    <select class="form-control"style="display:inline; float:right" ng-model="requestdata.units.length"  ng-options="value.id as value.label group by value.group for value in lengthUnits" ng-change="validateLength()">
        <option value="" selected hidden />
    </select>
</div>
<div class="item item-input item-stacked-label item-custom-second pull-right">
    <span class="positive"  ng-bind-html="translatedData.lengthField"></span>
    <div class="number number" >
    <input  class="form-control" type="number" name="length" placeholder="Value"
           ng-model="requestdata.beltSystem.length"
           ng-required="true" ng-blur="validateLength()">
        </div>
</div>

CSS

.item-custom-first select{
    width: inherit !important;
}
.item-custom-second div{
    display: inline-flex !important;
   width: auto !important;
    margin-right: 5px;
}