Subset based on one value in multiple columns

Question

I have a dataset with weekly number of lucky days for some of those weekly values i have values greater than 7 which must be a mistake.

Therefore what I want to do is to delete rows which have a value greater than 7 in one of the multiple columns. Those columns are column 21 to 68. What I have tried so far is this:

new_df <- subset(df, 21:68 <= 7) 

This leaves me with an completely empty new_df.

I know there is a option that goes like this:

new_df <- subset(df, b != 7 & d != 7)

But I feel like there must be a more elegant way than to name every single column which I want to refer to. Do I need to use square brackets or sth. like that? There is no Error message when computing the above mentioned command. The referred values are numerical.

Can someone help?