Truncating SQL DateTime in SQL Server 2008

Recently a coworker was writing a T-SQL script to compare ten-minute timeslices against each other. He was trying to figure out an easy, performant way to remove the ones place so that he could treat all timeslices from 01:00.00 to 01:09.99 as the same datetime, and so on. I found a few StackOverflow resources like this one but none that did exactly what I wanted. I adapted those with some trial and error into this:

Ten Minute Time Slices - TIL.sql 
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DECLARE @testDate DATETIME = '2016-05-13 12:57:21.097'

select dateadd(minute, (datepart(minute, @testdate) / 10) * 10, dateadd(hour, datediff(hour, 0, @testDate), 0)),
     dateadd(minute, (datepart(minute, @testdate) / 10) * 10 + 10, dateadd(hour, datediff(hour, 0, @testDate), 0))