There are a number of math functions in T-SQL. Here are a few of them:
SELECT SQRT(49) --Gives 7, Square Root
SELECT PI() --Gives 3.14 .... PI
SELECT ROUND(15.30, 0) --Gives 15. Rounds a number
SELECT CEILING(49.32) --Gives 50. Finds the next highest Integer value
SELECT FLOOR(49.32) --Gives 49. Finds the next lowest Integer value