In lots of digital appliances, numbers and letters are written with straight lines. For example, in digital clocks numbers are written that way. Calculators also have numbers and some letters in straight lines. The countdown timer in traffic signals also makes use of numbers written in the same manner. Additionally, computers and mobile phones also have a similar feature with their letters and numbers. Devices used in our households like washing machines, microwave oven, air conditioner, etc have numbers and letters written in the same format.