3. Without moving your head or the ruler open the left eye and close the right eye. Read the number that lines up with the centre of the pupil of the left eye. This number represents your Distance PD in millimetres. You have just used this technique to measure your distance PD. 4.
Lift the receiver and listen for the dial tone. Enter *74. Press a number between 2 and 9. This is your Speed Dial digit. Dial the phone number you want to assign to this digit. Note: For domestic long-distance calls, dial 1 plus the area code and then the phone number.
Speed dial was introduced in the early 1960s, and was displayed at the Bell Systems Pavilion at the 1962 World's Fair. This system used punch cards to store the phone numbers, and when someone wished to dial a particular number, the corresponding punch card was fed through a slot on the phone and dialed automatically. However, speed dial did not become common until the 1980s when touch tone phones had become commonplace.