How would I add onto a OffsetStud's value?

Of course, it doesn't work, but here is what I tried:

local HorizontalOffset = script.Parent.OffsetStudsU
local VerticalOffset = script.Parent.OffsetStudsV
while true do
    VerticalOffset.Value + 0.1
    HorizontalOffset.Value + 0.1
    wait(.01)

end

I'm just wondering how to add onto the value because I want to make an animated texture, I'm just not sure how to add to the number.