He was calculating in his head.

He understands the process of rationalization.

He is working hard to rationalize the equation.

We are considering introducing a new voting system.

We have developed a new methodology to solve this problem.

Learning a new input method is difficult.

There is a class observation at my son's school tomorrow.

The use of mobile phones is prohibited during class.

This math problem can be solved using a specific formula.

We have our wedding ceremony tomorrow.