Use this formula:

INT({Number Field}) & .9

Thx it worked but it multiplie by 10

21.4 > after the formula > 210.9

Why ?

I forgot that Airtable doesn’t like the & symbol for numbers… it will only respond properly to the + symbol.

So change it to + instead of &, and also, be sure to change the formatting of the field to decimal instead of integer.

So change the formula to this instead:

INT({Number Field}) + .9

And change the formatting of the field to decimal.