There have been a number of different approaches discussed below.

Still, tests are underway on a number of interesting approaches.

There are a number of different approaches being taken to the problem.

There are a number of different approaches to system analysis.

There are a number of different approaches to implementing them.

In the literature, a number of different approaches have been proposed based on this idea.

"It gives us a number of approaches on the market."

A number of approaches may be used to achieve this goal.

Businesses around the county have taken a number of approaches.

The government has tried and discarded any number of approaches in response.