To round off to nearest Multiple

Floor Rounding off to nearest multiple.

Number Rounded Down
1.5 1 =FLOOR(C4,1)
2.3 2 =FLOOR(C5,1)
2.9 2 =FLOOR(C6,1)
123 100 =FLOOR(C7,50)
145 100 =FLOOR(C8,50)
175 150 =FLOOR(C9,50)

What Does It Do ?
This function rounds a value down to the nearest multiple specified by the user.

Syntax
=FLOOR(NumberToRound,Significant Value)