https://doc.rust-lang.org/std/fmt/#precision ```rust let x = "123.456" assert_eq!(format!("{x:.0}"), "12"); assert_eq!(format!("{x:.1}"), "12.3"); assert_eq!(format!("{x:.2}"), "12.35"); assert_eq!(format!("{x:.3}"), "12.345"); assert_eq!(format!("{x:.4}"), "12.3450"); ```