Rounding numbers on GUIs to the nearest hundredth

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#1

  1. What do you want to achieve? I want to have my decimal rounded to the nearest 2nd decimal point.

  2. What is the issue?

player.PlayerGui.Stats.Frame.Upgrades.UpgradeSpeed.Text = player.Stats.Speed.Value /70

this script can sometimes output some number with a massive amount of decimals and I can’t think of a way to solve this.

  1. What solutions have you tried so far? I tried looking for solutions on the devforum but all I could find was for rounding to the nearest whole number and shortening numbers (example 2k)
4 Likes
#2

I believe what you could do here is divide your number by 100, as to make it a 2 point decimal, use either your math.floor() or math.ceil() rounding option and then times it by 100 again. This way, you can round it as a decimal and then get your original number back.

I tested it in studio and it seemed to work, so your code would look something like this.

player.PlayerGui.Stats.Frame.Upgrades.UpgradeSpeed.Text = math.floor((player.Stats.Speed.Value / 100)) * 100

Edit: Sorry, misread your question, I’ll reconfigure this code to make it to 2 d.p

Edit 2: After some googling, I found this formula, which will return your number to 2 d.p.
math.floor( (val * 10^num) + 0.5) / (10^num))

I hope it works for you! :smiley:

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#3 
script.Parent.Text = "+" .. Damage.Value /70 .. " speed for " .. Damage.Value *300 .. " Coins."

the “val” and “num” seem to be variables but what do I fill in for them, is “val” the “damage.value” and num the “70” I tried

"+" .. math.floor( (Damage.Value * 10^70) + 0.5) / (10^100)

but that outputted “+1e-30”, a number I have never seen in my life

#4

That’s because you’re doing 10 to the power of 70 and dividing it by 10 to the power of 100.

num is simply how many d.p you want, so num would equal 2 in this situation. Sorry for the confusion.

1 Like
#5

For anyone confused how math.floor(x * 10^n) / (10^n) actually works here is an explanation.

The x * 10^n is meant to shift x by n places. So if you have the number 10.25 and multiply by 10^2 which is 100 that leaves you with 1025. Given this logic you could now floor the number which will cut off the remaining decimal portion if there was any and then divide by the original 10^n because you want to put your number back to the same significant figures.

Values showing 1.8399999... when in a GUI, but in the properties it is 1.84
#6

This works if you still need it.

local roundDecimals = function(num, places) --num is your number or value and places is number of decimal places, in your case you would need 2
    
    places = math.pow(10, places or 0)
    num = num * places
   
    if num >= 0 then 
        num = math.floor(num + 0.5) 
    else 
        num = math.ceil(num - 0.5) 
    end
    
    return num / places
    
end

print(roundDecimals(142.165, 2)) --> 142.17
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How to make a decimal that only shows hundredths
#7

this problem is very simple to solve!

local Number = 0  -- put your number here
TextLabel.Text = string.format('%.2f%% of Speed', Number)

I hope I have been helpful. :smile:

in the place of ("%.2f%%), you can change the value “2” to how many decimal places you want to appear

2 Likes
#8

He wanted to round the decimals though

#9

the %f pattern automatically does decimal rounding.

image

2 Likes
#10 
math.floor( (Speed.Value * 10^2) + 0.5) / (10^2)

IDK whats wrong with my script! the speed value is 16 and this outputs 16! It is supposed to output less then one

Edit: this now has a solution! thanks everyone!

Better guide to roblox strings and formatting?
#11

Doesn’t seem to round them properly all the time from what I’ve tested though, I tried printing out the same number (14.4215) using both methods and got out 14.421 with this method above and 14.422 with the one I posted. But I guess that doesn’t really matter.

#12 
local percentage = Speed.Value / 70 * 100

print((math.floor(percentage * 100 + 0.5) / 100).."%")
-- OR
print(("%.2f%%"):format(percentage))

The string formatting method will keep the “.00” even if it’s a round number, the math.floor method doesn’t.

#13

Cheat code:
Use the %d pattern instead to remove the padding!

image

It does not do rounding though, it just removes the decimal portion. To do rounding add .5 to x;

("%d"):format(x + .5)

image

(For anyone wondering this works because if the first decimal place is greater than .5 that means you round up, and adding .5 effectively rounds it up and on the floor portion of the math (%d pattern) the decimal portion gets removed)