This required a large number of members to make it.

This required a number of design changes to reduce costs.

Thus far, it had determined two of the seven numbers required to open the door.

The number required to win the game is one hundred, but it may be made less by agreement.

Some 12,000 people visit the cave every year, well below the number required to break even.

Some passes require a specific number of players to form the team.

And at that power level the government requires a number of safety features.

They also required a number of major labor union concessions.

The march would be dramatic, but not require large numbers of participants.

However, such pyramids required a very large number of boys.