title: C# how to always round down to nearest 50
body: <p>I've done a search on C# rounding, but haven't been able to find the answer to my current problem.</p>
  
  <p>What I want to do is always round down to the nearest 50. All the values I want to round down will be in decimal.</p>
  
  <p>So 635.25 would be 600.</p>
  
  <p>298.42 would be 250.</p>
  
  <p>149.56 would be 100.</p>
  
  <p>I've looked at math.round but how would I use that so it always rounds down to the nearest 50 and never up?</p>