How to make blocks shrink?

like touching a block it will shrink

block.Touched:connect(function()
	local cf=block.CFrame
	block.Size=block.Size-Vector3.new(1,1,1)
	block.CFrame=cf
end)

This will reduce the size of the block by 1 in all dimensions. (min .2 for custom parts, 1 for Symmetric, 1.2 for Brick, 2 for trusses)