Replace multiple values over multiple columns of a data frame in R

I am trying to replace certain numbers with others over multiple columns of a data set.

1=1
2=1
3=2
4=3
5=3

So if I have:

id      age        A1       weight     Var1       A2    
  
3       5          2         50         1         4
7       23         1         67         5         3
9       78         4         90         3         2
12      14         1         17         2         3

I want to replace those numbers in columns A1, Var1, and A2

id      age        A1       weight     Var1       A2    
  
3       5          1         50         1         3
7       23         1         67         3         2
9       78         3         90         2         1
12      14         1         17         1         2

I think I can do something with mutate_across but I'm not sure