Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Dim M As Long
If Target.CountLarge > 1 Then Exit Sub
If Not Intersect(Target, [C2:Q6]) Is Nothing Then
M = Cells(Target.Row, "B").Value
Application.EnableEvents = False
Target.Value = -Int(-Target.Value / M) * M
Application.EnableEvents = True
End If
End Sub