How it works
The number pad is a calculator grown right into the keyboard. It sits at the right, so the right hand can work it alone, and its keys are close together.
On the pad the numbers climb up from the bottom: seven, eight and nine along the top, and one, two and three along the bottom.
The pad has a home row too, four, five and six: pointer on the four, middle finger on the five and ring finger on the six. The five has a little bump, and the thumb rests on the zero.
A laptop with no pad can use the number row, which does the same job a little slower.