What does * mean in XAML. I have a grid of width 400. And divided the grid to 3 columns. What does *.4 mean? I thought it is 40% of the space available. so thought the first 2 columns will get 40% percent each and the rest is taken by the third column. but looks like, the third column is taking 60% and the first two are getting 20% each. How does this work?

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width=".4*"/>
        <ColumnDefinition Width=".4*"/>
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
</Grid>

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wpf xaml expression-blend
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