How would I make a bigger grid to snap to?

So I managed to create a basic grid system where you move an object (Part or Model) to each stud. This is working but I want to know how to add to the grid. Instead of it being moved to each stud maybe every 4 or 5 studs.

Here is my code:

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
local Part = workspace.Movement.PrimaryPart -- The model that I am moving

Mouse.Move:Connect(function()
    local PosX = math.ceil(Mouse.Hit.X) -- I also used math.floor()
    local PosY = 11.1 -- The current y position of the model's primaryPart
    local PosZ = math.ceil(Mouse.Hit.Z) -- I also used math.floor()

    -- Moving the model
    Part.Parent:MoveTo(Vector3.new(PosX, PosY, PosZ))
end)

I have tried added values to the Pos variables (lines 6-8) and it just creates a bigger problem. Thanks to who helps me!