How to round to the nearest hundredth?

This isn't too hard. There might be a better way, but as an example, you can use math.floor. This rounds to the nearest whole number:

--// Nearest Whole Number
local function round(num)
    return math.floor(num+0.5)
end

You can change this to round to tenths:

--// Nearest Tenth
local function round(num)
    return math.floor(((num*10)+0.5))/10
end

And so on:

--// Nearest Hundredth
local function round(num)
    return math.floor(((num*100)+0.5))/100
end