Спасибо!Извините, я забыл указать код:
$(document).ready(function() {
$('#showFive').click(function(){
jQuery('.targetDiv').show();
});
$('#showFour').click(function(){
jQuery('.targetDiv').hide();
jQuery('#div1,#div2,#div3,#div4').show();
});
$('#showThree').click(function(){
$('.targetDiv').hide();
$('#div4,#div5').hide();
$('#div1,#div2,#div3').show();
});
$('#div1, #vdiv2, #div3, #div4, #div5').keyup(function(){
var div1 = parseFloat($('#div1').val()) || 0;
var div2 = parseFloat($('#div2').val()) || 0;
var div3 = parseFloat($('#div3').val()) || 0;
var div4 = parseFloat($('#div4').val()) || 0;
var div5 = parseFloat($('#div5').val()) || 0;
$('#sum').val(div1 + div2 + div3 + div4 + div5); // values (or variables) here
});
});
body{
width:100%;
height:100%;
background: #eee;
}
div.menu{
margin: 5% 10%;
background: transparent;
}
.targetDiv{
display:none;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<link rel="stylesheet" type="text/css" href="style.css">
<title>Dividing money</title>
</head>
<body>
<div>
<input type="number" id="money" value="100" max="100" readonly />
<div class="menu">
<a id="showThree" target="1">3 boxes</a>
<a id="showFour" target="3">4 boxes</a>
<a id="showFive">5 boxes</a>
</div>
<form>
<div>
<input type="number" id="div1" class="targetDiv" placeholder="Number1" min="???" step="0.5"/>
<input type="number" id="div2" class="targetDiv" placeholder="Number2" min="???" step="0.5"/>
<input type="number" id="div3" class="targetDiv" placeholder="Number3" min="???" step="0.5"/>
<input type="number" id="div4" class="targetDiv" placeholder="Number4" min="???" step="0.5"/>
<input type="number" id="div5" class="targetDiv" placeholder="Number5" min="???" step="0.5"/>
</div>
<input type="number" id="sum"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
<script src="scripts.js"></script>
</body>
</html>