How to create a milliseconds timer without it skipping 0.1 second sometimes?

I am trying to make a milliseconds timer using localscript, but it seems to be skipping 0.1 second sometimes.

Here is my script:

wait(1)
local StartTick = tick()

while true do
    local Second = tick() - StartTick
    Second = Second * 10
    print("original second: "..Second)
    Second = math.floor(Second)
    Second = Second / 10
    script.Parent.Timer.TextLabel.Text = Second
    print("fixed second: "..Second)
    wait(0.1)
end

I put print for original second and fixed second, here's the output: https://i.gyazo.com/afe8fc2411ea85a8f473dac7c7a4c6a0.png