This is my simple function ... var x = msg.payload; var temp = x.toFixed(1); var tempNumber = parseFloat(temp); var z = (tempNumber + 0.3); node.status(tempNumber + " - " + z); global.set("var_temperaturaCamerina", z); msg.payload = z; return msg; Look at the node status and the "z" value ... Why…

Try var x = msg.payload; var tempNumber = Math.round(x*10)/10; var z = (tempNumber + 0.3); node.status(tempNumber + " - " + z); global.set("var_temperaturaCamerina", z); msg.payload = z; return msg; or var x = msg.payload; var z = (x + 0.3); node.status(x.toFixed(1) + " - " + z.toFixed(1)); globa…

I tried to reproduce it, but here your code works as you expect.... So I would guess a node or system setting. [image] I tried it on windows and linux node red 2.2.

Your 2° example work fine for me .... :+1: (not the 1°)

The reason your original version does not do what you expect is rounding errors in the floating point arithmetic. Any time you do arithmetic there is the possibility of rounding errors. The solution, as you have seen, is to round to the required precision when you want to display it, not before.

Why don’t my numbers, like 0.1 + 0.2 add up to a nice round 0.3, and instead I get a weird result like 0.30000000000000004? Because internally, computers use a format ( binary floating-point ) that cannot accurately represent a number like 0.1, 0.2 or 0.3 at all . When the code is compiled or interpr…

Ok, thank you for explanation .....

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Sum number error?

General

Giamma 26 February 2022 16:50 5

Your 2° example work fine for me .... (not the 1°)

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Sum number error?

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