# Formatting number to 2 digits; just cosmetics ;-) **URL:** \ **Category:** Flows\ **Created:** [October 30, 2020, 11:09am UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734 "2020-10-30T11:09:52Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![pvkan](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pvkan/32/16433_2.png) [@pvkan](https://community.homey.app/u/pvkan)\ **Post date:** [October 30, 2020, 11:09am UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/1 "2020-10-30T11:09:52Z")
Hi, I use the ‘Wasmachine’ flow to be noticed when the washingmachine has finished. As an addition i also calcultate the costs of the power used. With mathjs i round this calculation to 2 digits behind the separator. Sometimes the calculation gives 20 cents. This is noted as € 0,2 in the message i send to myself. Just for cosmetic reasons: Is there a way to format this into € 0,20 (2 digits so with the 0 added) in mathjs ? (number to string) Like something as: usedpower$ = format$(number, € ##,00) Peter ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [October 30, 2020, 12:10pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/2 "2020-10-30T12:10:44Z")
If Homey supports all of MathJS, you should be able to use this: ```auto format(VALUE, { precision: 2 }) ``` This will also perform the rounding operation. ---
**Author:** ![pvkan](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pvkan/32/16433_2.png) [@pvkan](https://community.homey.app/u/pvkan)\ **Post date:** [October 30, 2020, 12:42pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/3 "2020-10-30T12:42:18Z")
@robertklep Thanks for the quick repsonse; unfortunatly it does not work; Homey does not recognize ‘format’. Yhx Peter ---
**Author:** ![Wessel](https://avatars.discourse-cdn.com/v4/letter/w/53a042/32.png) [@Wessel](https://community.homey.app/u/Wessel)\ **Post date:** [October 30, 2020, 1:37pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/4 "2020-10-30T13:37:22Z")
Maybe round will work: From @Canedje: something like this wil work: {{round (Energiekosten vandaag,2)}} the 2 means 2 digits after the , in your case {{round(Target temperature,1)}} ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [October 30, 2020, 1:45pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/5 "2020-10-30T13:45:21Z")
He already used `round()`, but that function will drop any trailing zero’s. ---
**Author:** ![pvkan](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pvkan/32/16433_2.png) [@pvkan](https://community.homey.app/u/pvkan)\ **Post date:** [October 30, 2020, 7:32pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/6 "2020-10-30T19:32:38Z")
Yep, using it already. Round does not ‘format’ the number. Peter ---
**Author:** ![Marcel\_Ubels](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/marcel_ubels/32/18860_2.png) [@Marcel\_Ubels](https://community.homey.app/u/Marcel_Ubels)\ **Post date:** [October 31, 2020, 9:59pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/7 "2020-10-31T21:59:05Z")
Maybe adding 0.000001 to the outcome, than Round and extract 0.000001. Maybe you have to round it again. ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [April 19, 2021, 3:10pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/8 "2021-04-19T15:10:06Z")
Hi all. About the `format()` funtion. It _looks like_ it isn’t supported? I’m no coder, so be warned 😉 Maybe Robert knows what I’m doing wrong here? I want a number to be formatted as n.0 (always display the zero) and found this [at math.js](https://mathjs.org/docs/reference/functions/format.html): ```auto math.format(2.3, {notation: 'fixed', precision: 4}) // returns '2.3000' ``` _(In case of notation ‘fixed’, `precision` defines the number of significant digits after the decimal point)_ So, with this Logics card ‘calc a value’, I want to accomplish 100 to be shown as 100.0 like this, but I get NaN values returned. - I tried this: ```auto {{format(100, { notation: 'fixed', precision: 1 })}} {{format(100, { 'fixed', precision: 1 })}} {{format(100, { fixed, precision: 1 })}} {{format(100, { precision: 1 })}} {{format(100, { 1 })}} ``` Something else: This should round to 1000, but it also returns NaN: ```auto {{format(1234, 2)}} ``` **Background of what I’d like to accomplish:** - Vars used: - - `` - a Logics NumericVar - - `` - a value between 0 and 2000 form a airpressure sensor VirtualDevice type Thermostat - should display 100.5 or 100.0 as airpressure Calculate `` as ```auto {{format(/10, { notation: 'fixed', precision: 1 })}} ``` Flow: ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [April 19, 2021, 5:50pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/9 "2021-04-19T17:50:45Z")
> [@Peter\_Kawa](#): > > This should round to 1000, but it also returns NaN: > > ```auto > {{format(1234, 2)}} > > ``` Not sure what you’re doing wrong, that works just fine for me: ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/b/6/b60a1a3d5aebb71baf555b967cb4a62acfa6c022.png) and the result: ![IMG_9FC06C58EF6D-1](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/2/f/2f8893c698e2993e04a28d51a0b4199c45c027bf.jpeg) What also works is this: ```auto {{ format(1234, { precision : 1, notation: "fixed" }) }} ``` If you use single quotes (or back quotes) it stops working. I guess Athom still hasn’t worked out the parsing issues in flow cards. ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [April 19, 2021, 6:47pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/10 "2021-04-19T18:47:06Z")
Thanks, Robert. Glad to know the function itself works. I can’t see the difference either. I will continue trying, maybe creating a new flow might help. Cheers ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [April 19, 2021, 7:26pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/11 "2021-04-19T19:26:00Z")
This worked for me as well, Robert, using the math directly in the push message ![Screenshot_20210419-205747_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/2/e/2eee3d4fc63076589e1744d6546fe4b408f249c5.jpeg) I found out it doesn’t work with the native logic “calculate a value” card, the result is an empty num var: ![Screenshot_20210419-211854_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/e/1/e1c9f977e223486e1112d90c42020ca8a71a7367.jpeg) But, it works a little bit with better logic “Execute matjs expression” card, but the result stays zero ![Screenshot_20210419-211629_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/d/6/d6ffff11d9f48acee83eeeb35a63f9f52fcec39d.jpeg) Again, in the push message it works fine. ![Screenshot_20210419-214503_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/8/f/8f35dd02fffb7e3e83d3fdfabc356fe6aa79e37b.jpeg) ![Screenshot_20210419-213830_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/8/8/88d63ddd6abb0219544758a7cc0411b858df4d16.jpeg) Now I have to find out how to get the calculated value into the virtual thermometer… ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [April 20, 2021, 5:33am UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/12 "2021-04-20T05:33:10Z")
Perhaps try variable names without mathematical operators (`-`) in their names. ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [April 20, 2021, 12:26pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/13 "2021-04-20T12:26:14Z")
Thanks Robert. I realized this and changed the var name a few times. First I used a `/` sign and before that a `.` sign. Will now try without special characters. ---
**Author:** ![Nigel\_Scott](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/nigel_scott/32/10602_2.png) [@Nigel\_Scott](https://community.homey.app/u/Nigel_Scott)\ **Post date:** [January 24, 2023, 11:02am UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/14 "2023-01-24T11:02:51Z")
Is there a way to get the output to exclude the " " I am wanting to turn a number (23) into 23.0 but the results outputs as “23.0” and the web command then fails. ---
**Author:** ![robertklep](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/robertklep/32/160628_2.png) [@robertklep](https://community.homey.app/u/robertklep)\ **Post date:** [January 24, 2023, 12:11pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/15 "2023-01-24T12:11:28Z")
It seems that the flow cards are adding these (possibly because they are using some sort of JSON formatting). I don’t know if there’s a way of removing them. ---
**Author:** ![Erlend63](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/erlend63/32/38414_2.png) [@Erlend63](https://community.homey.app/u/Erlend63)\ **Post date:** [December 25, 2025, 3:13pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/16 "2025-12-25T15:13:51Z")
This is a follow-up to the thread [Formatting number to 2 digits; just cosmetics 😉](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734), I have a similar requirement I would like to implement. I have a number variable with multiple digits that I want to assign to a string variable with control of the format. In Perl (yes, old guy here…), this would look like this: my $fEnergyDiff=1.23456789; my $strEnergyDiff=sprintf(“%.2f”,$fEnergyDiff); printf “diff=$strEnergyDiff\n”; This would produce the string “diff=1.23”. If I can do this in a Homey flow, I can use the string variable (strEnergyDiff) everywhere I need it, for example in log entries or in push messages. Here is the test flow I have for this: ![2025-12-25 16_08_16-_new 3 - Notepad++](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/9/f/9f33953746219c736db7e79625ebae8bdcc03f2d.png) When I run this, I get this in the Timeline: “fEnergyDiff=1.23456789, strEnergyDiff=1.23456789" (from step #3), as expected. So, is it possible to do some clever JS stuff in step #2 so that the string variable will be assigned 1.23 and I get “fEnergyDiff=1.23456789, strEnergyDiff=1.23" in the Timeline? I did try some of the suggestions in the linked thread, but got nowhere. ---
**Author:** ![Adrian\_Rockall](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/adrian_rockall/32/13209_2.png) [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)\ **Post date:** [December 25, 2025, 4:22pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/17 "2025-12-25T16:22:13Z")
Have you tried using: > const stringObj = numObj.toFixed(2) ---
**Author:** ![Erlend63](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/erlend63/32/38414_2.png) [@Erlend63](https://community.homey.app/u/Erlend63)\ **Post date:** [December 25, 2025, 5:29pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/18 "2025-12-25T17:29:43Z")
Well, I tried, but I am pretty sure I did not do this correctly: ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/6/164b3feaa142b482bf0fdaf05632fc08885f89b7.png) This produced the following in the Timeline: “fEnergyDiff=1.23456789, strEnergyDiff={{1.23456789.toFixed(2)}}”. What is the syntax for using the toFixed function on the fEnergyDiff object and assign it to strEnergyDiff? ---
**Author:** ![Adrian\_Rockall](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/adrian_rockall/32/13209_2.png) [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)\ **Post date:** [December 25, 2025, 6:29pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/19 "2025-12-25T18:29:11Z")
I think you will need to use the calculate card to round the number and then convert that to text. ![Screenshot_20251225_182832_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/a/6/a6c0ef8939311db4a17a17a020a9d22f762c7f53.jpeg) ---
**Author:** ![Erlend63](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/erlend63/32/38414_2.png) [@Erlend63](https://community.homey.app/u/Erlend63)\ **Post date:** [December 25, 2025, 9:58pm UTC](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734/20 "2025-12-25T21:58:50Z")
Thanks, this seems to work fine: ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/9/d/9d14e051d7825fe57f4207e2ebf98e411e1f173f.png) When I run this, card #2 does the rounding and card #4 produces the correct 2-decimal numbers in the Timeline. Since Num already has 2-decimals (due to the round function), I don’t really need the Str variable (card #3). I found during this testing that card #1 doesn’t work, the setting of this variable is ignored, the calculation in card #2 uses the value I set in the web interface instead (from the Variables button in the flow editor), card #1 is ignored. I am not sure why this happens - maybe somebody can explain it. Anyway, thanks Adrian - your tip did the trick! /Erlend [Next page](https://community.homey.app/t/formatting-number-to-2-digits-just-cosmetics/36734.md?page=2)