The artillery fired a four-pounder.

I prefer driving a car with four-wheel drive.

I saw a four-wheeler parked outside the house.

He wore plus fours for the golf game.

I enjoyed a delicious petit four at the bakery.

Four score and seven years ago...

I joined the Four-H club to learn about agriculture and home economics.

I found a four-leaf clover in the park.

He used a four-letter word when he got angry.

I found a four-leaved clover in the park.