The A-6s were used extensively during the Vietnam War.

There are six 6s in the box.

The 4-8-6s are powerful locomotives.

The 6-8-6s are on sale today.

There are many 2-6-6s in the train museum.

The 2-8-6s are powerful locomotives.

The 6-4-4-6s in the parking lot are all luxury cars.

The 2-6-6-6s are powerful steam locomotives.