The number guessing game is quite simple. In this game the player thinks any number between 1 to 99 and then if same number is displayed on screen, he wins otherwise player looses the game. This simple circuit is based on two IC’s namely NE555 which is a timer IC. In this circuit we are utilizing it astable mode. And another one that we are using is 4026, which is a decade counter/divider IC. It converts the input into numeric display without any decoder IC which can be seen on 7 segment display. In this circuit NE555 astable generates a clock for the circuit, which provides a oscillating wave to the output pin 3 of IC1. The time period of counter can be calculated by following formula T = 0.7 (R1 + 2*R2)*C1.