I have a problem with this code :

```
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                   xmlns:s="library://ns.adobe.com/flex/spark"
                   xmlns:mx="library://ns.adobe.com/flex/mx"
                   showStatusBar="false"
                   width="250" height="31">
<s:layout>
    <s:HorizontalLayout gap="10" paddingBottom="10" paddingLeft="10" paddingRight="10"
                        paddingTop="10" verticalAlign="middle"/>
</s:layout>
<fx:Script>
    <![CDATA[
        [Bindable]
        private var i:Number = 1.0;

        private function click(e:MouseEvent):void
        {
            if (e.currentTarget == plus)
                i += .1;
            if (e.currentTarget == minus)
                i -= .1;
        }
    ]]>
</fx:Script>
<s:Button id="plus" width="30" label="+" click="click(event)"/>
<s:Button id="minus" width="30" label="-" click="click(event)"/>
<s:Label text="{i}"/>

```

When I click on '+' I get  

1.1 (OK)  

1.2000000000000002 (instead of 1.2)  

1.3000000000000003 (instead of 1.3)  

1.4000000000000004 (instead of 1.4)  

1.5000000000000004 (instead of 1.5)  

1.6000000000000005 (instead of 1.6)  

1.7000000000000006 (instead of 1.7)  

1.8000000000000007 (instead of 1.8)  

1.9000000000000008 (instead of 1.9)  

2.000000000000001 (instead of 2.0)  

...  

And when I click on '-' I get  

0.9 (OK)  

0.8 (OK)  

0.7000000000000001 (instead of 0.7)  

0.6000000000000001 (instead of 0.6)  

0.5000000000000001 (instead of 0.5)  

0.40000000000000013 (instead of 0.4)  

0.30000000000000016 (instead of 0.3)  

0.20000000000000015 (instead of 0.2)  

0.10000000000000014 (instead of 0.1)  

1.3877787807814457e-16 (instead of 0.0)  

...  

I change my function by  

```
private function click(e:MouseEvent):void
{
    if (e.currentTarget == plus)
        i = Math.floor((i + 0.1) * 10) / 10;
    if (e.currentTarget == minus)
        i = Math.floor((i - 0.1) * 10) / 10;
}

```

I get the right number when I click on only '+' or only on '-'  

But if I click '-' until 0.7 and '+', it stays at 0.7  

The same append when I click '-' until 0.9 when '+', it stay to 0.8  

Why? How can I do to increment or decrement a Number by 0.1?